KSP - Low-level Interface

This page documents the low-level, automatically wrapped PETSc KSP (Krylov Subspace Methods) functions available through LibPETSc. These functions provide direct access to the PETSc C API.

For the high-level Julia interface, see KSP.

Overview

The KSP interface includes:

Core KSP operations: Linear solver creation, configuration, and solution (~244 functions in KSP_wrappers.jl)
KSPGuess: Initial guess generation for iterative solvers (~12 functions in KSPGuess_wrappers.jl)

Usage

All low-level KSP functions require a petsclib parameter as the first argument:

using PETSc

# Get the library instance
petsclib = PETSc.petsclibs[1]
PETSc.initialize(petsclib)

# Get PETSc types
PetscInt = petsclib.PetscInt

# Assume mat, b, x are already created

# Create KSP solver
ksp = LibPETSc.KSPCreate(petsclib, LibPETSc.PETSC_COMM_SELF)
LibPETSc.KSPSetOperators(petsclib, ksp, mat, mat)
LibPETSc.KSPSetFromOptions(petsclib, ksp)

# Solve Ax = b
LibPETSc.KSPSolve(petsclib, ksp, b, x)

# Get convergence info
reason = LibPETSc.KSPGetConvergedReason(petsclib, ksp)

iterations = LibPETSc.KSPGetIterationNumber(petsclib, ksp)

# Clean up
LibPETSc.KSPDestroy(petsclib, ksp)
PETSc.finalize(petsclib)

Function Reference

PETSc.LibPETSc.KSPAppendOptionsPrefix — Method

KSPAppendOptionsPrefix(petsclib::PetscLibType,ksp::PetscKSP, prefix::String)

Appends to the prefix used for searching for all KSP options in the database.

Logically Collective

Input Parameters:

ksp - the Krylov context
prefix - the prefix string to prepend to all KSP option requests

Level: intermediate

-seealso: , KSP, KSPSetOptionsPrefix(), KSPGetOptionsPrefix(), KSPSetFromOptions()

External Links

PETSc Manual: KSP/KSPAppendOptionsPrefix

source

PETSc.LibPETSc.KSPBCGSLSetEll — Method

KSPBCGSLSetEll(petsclib::PetscLibType,ksp::PetscKSP, ell::PetscInt)

Sets the number of search directions to use in the KSPBCGSL Krylov solver

Logically Collective

Input Parameters:

ksp - iterative context, KSP, of type KSPBCGSL
ell - number of search directions to use

Options Database Key:

-ksp_bcgsl_ell ell - Number of Krylov search directions

Level: intermediate

-seealso: , KSPBCGSLSetUsePseudoinverse(), KSP, KSPBCGSL, KSPBCGSLSetPol(), KSPBCGSLSetXRes()

External Links

PETSc Manual: KSP/KSPBCGSLSetEll

source

PETSc.LibPETSc.KSPBCGSLSetPol — Method

KSPBCGSLSetPol(petsclib::PetscLibType,ksp::PetscKSP, uMROR::PetscBool)

Sets the type of polynomial part that will be used in the KSPCBGSL KSPSolve()

Logically Collective

Input Parameters:

ksp - iterative context of type KSPCBGSL
uMROR - set to PETSC_TRUE when the polynomial is a convex combination of an MR and an OR step.

Options Database Keys:

-ksp_bcgsl_cxpoly - use enhanced polynomial
-ksp_bcgsl_mrpoly - use standard polynomial

Level: intermediate

-seealso: , KSP, KSPBCGSL, KSPCreate(), KSPSetType(), KSPCBGSL, KSPBCGSLSetUsePseudoinverse(), KSPBCGSLSetEll(), KSPBCGSLSetXRes()

External Links

PETSc Manual: KSP/KSPBCGSLSetPol

source

PETSc.LibPETSc.KSPBCGSLSetUsePseudoinverse — Method

KSPBCGSLSetUsePseudoinverse(petsclib::PetscLibType,ksp::PetscKSP, use_pinv::PetscBool)

Use pseudoinverse (via SVD) to solve polynomial part of the update in KSPCBGSL solver

Logically Collective

Input Parameters:

ksp - iterative context of type KSPCBGSL
use_pinv - set to PETSC_TRUE when using pseudoinverse

Options Database Key:

-ksp_bcgsl_pinv <true,false> - use pseudoinverse

Level: intermediate

-seealso: , KSPBCGSLSetEll(), KSP, KSPCBGSL, KSPBCGSLSetPol(), KSPBCGSLSetXRes()

External Links

PETSc Manual: KSP/KSPBCGSLSetUsePseudoinverse

source

PETSc.LibPETSc.KSPBCGSLSetXRes — Method

KSPBCGSLSetXRes(petsclib::PetscLibType,ksp::PetscKSP, delta::PetscReal)

Sets the parameter governing when exact residuals will be used instead of computed residuals for KSPCBGSL.

Logically Collective

Input Parameters:

ksp - iterative context of type KSPBCGSL
delta - computed residuals are used alone when delta is not positive

Options Database Key:

-ksp_bcgsl_xres delta - Threshold used to decide when to refresh computed residuals

Level: intermediate

-seealso: , KSPBCGSLSetEll(), KSPBCGSLSetPol(), KSP, KSPCBGSL, KSPBCGSLSetUsePseudoinverse()

External Links

PETSc Manual: KSP/KSPBCGSLSetXRes

source

PETSc.LibPETSc.KSPBuildResidual — Method

KSPBuildResidual(petsclib::PetscLibType,ksp::PetscKSP, t::PetscVec, v::PetscVec, V::PetscVec)

Builds the residual in a vector provided.

Collective

Input Parameter:

ksp - iterative solver obtained from KSPCreate()

Output Parameters:

t - work vector. If not provided then one is generated.
v - optional location to stash residual. If v is not provided, then a location is generated.
V - the residual

Level: advanced

-seealso: , KSP, KSPBuildSolution()

External Links

PETSc Manual: KSP/KSPBuildResidual

source

PETSc.LibPETSc.KSPBuildResidualDefault — Method

KSPBuildResidualDefault(petsclib::PetscLibType,ksp::PetscKSP, t::PetscVec, v::PetscVec, V::PetscVec)

Default code to compute the residual.

Collecive on ksp

Input Parameters:

ksp - iterative context
t - pointer to temporary vector
v - pointer to user vector

Output Parameter:

V - pointer to a vector containing the residual

Level: advanced

-seealso: , KSP, KSPBuildSolutionDefault()

External Links

PETSc Manual: KSP/KSPBuildResidualDefault

source

PETSc.LibPETSc.KSPBuildSolution — Method

KSPBuildSolution(petsclib::PetscLibType,ksp::PetscKSP, v::PetscVec, V::PetscVec)

Builds the approximate solution in a vector provided.

Collective

Input Parameter:

ksp - iterative solver obtained from KSPCreate()

Output Parameter: Provide exactly one of

v - location to stash solution, optional, otherwise pass NULL
V - the solution is returned in this location. This vector is created internally. This vector should NOT be destroyed by the user with VecDestroy().

Level: developer

-seealso: , KSPGetSolution(), KSPBuildResidual(), KSP

External Links

PETSc Manual: KSP/KSPBuildSolution

source

PETSc.LibPETSc.KSPBuildSolutionDefault — Method

KSPBuildSolutionDefault(petsclib::PetscLibType,ksp::PetscKSP, v::PetscVec, V::PetscVec)

External Links

PETSc Manual: KSP/KSPBuildSolutionDefault

source

PETSc.LibPETSc.KSPCGGetNormD — Method

KSPCGGetNormD(petsclib::PetscLibType,ksp::PetscKSP, norm_d::PetscReal)

Get norm of the direction when the solver is used inside SNESNEWTONTR

Not collective

Input Parameters:

ksp - the iterative context
norm_d - the norm of the direction

Level: advanced

-seealso: , KSP, KSPCG, KSPNASH, KSPSTCG, KSPGLTR, SNESNEWTONTR

External Links

PETSc Manual: KSP/KSPCGGetNormD

source

PETSc.LibPETSc.KSPCGGetObjFcn — Method

KSPCGGetObjFcn(petsclib::PetscLibType,ksp::PetscKSP, o_fcn::PetscReal)

Get the conjugate gradient objective function value

Not collective

Input Parameters:

ksp - the iterative context
o_fcn - the objective function value

Level: advanced

-seealso: , KSP, KSPCG, KSPNASH, KSPSTCG, KSPGLTR, KSPMonitorSet

External Links

PETSc Manual: KSP/KSPCGGetObjFcn

source

PETSc.LibPETSc.KSPCGSetObjectiveTarget — Method

KSPCGSetObjectiveTarget(petsclib::PetscLibType,ksp::PetscKSP, obj::PetscReal)

Sets the target value for the CG quadratic model

Logically Collective

Input Parameters:

ksp - the iterative context
obj - the objective value (0 is the default)

Level: advanced

-seealso: , KSP, KSPCG, KSPNASH, KSPSTCG, KSPGLTR, SNESNEWTONTR

External Links

PETSc Manual: KSP/KSPCGSetObjectiveTarget

source

PETSc.LibPETSc.KSPCGSetRadius — Method

KSPCGSetRadius(petsclib::PetscLibType,ksp::PetscKSP, radius::PetscReal)

Sets the radius of the trust region used by the KSPCG when the solver is used inside SNESNEWTONTR

Logically Collective

Input Parameters:

ksp - the iterative context
radius - the trust region radius (0 is the default that disable the use of the radius)

Level: advanced

-seealso: , KSP, KSPCG, KSPNASH, KSPSTCG, KSPGLTR, SNESNEWTONTR

External Links

PETSc Manual: KSP/KSPCGSetRadius

source

PETSc.LibPETSc.KSPCGSetType — Method

KSPCGSetType(petsclib::PetscLibType,ksp::PetscKSP, type::KSPCGType)

Sets the variant of the conjugate gradient method to use for solving a linear system with a complex coefficient matrix. This option is irrelevant when solving a real system.

Logically Collective

Input Parameters:

ksp - the iterative context
type - the variant of CG to use, one of

-seealso: , KSP, KSPCG

External Links

PETSc Manual: KSP/KSPCGSetType

source

PETSc.LibPETSc.KSPCGUseSingleReduction — Method

KSPCGUseSingleReduction(petsclib::PetscLibType,ksp::PetscKSP, flg::PetscBool)

Merge the two inner products needed in KSPCG into a single MPI_Allreduce() call.

Logically Collective

Input Parameters:

ksp - the iterative context
flg - turn on or off the single reduction

Options Database Key:

-ksp_cg_single_reduction <bool> - Merge inner products into single MPI_Allreduce()

Level: intermediate

-seealso: , , KSP, KSPCG, KSPGMRES, KSPPIPECG, KSPPIPECR, and KSPGROPPCG

External Links

PETSc Manual: KSP/KSPCGUseSingleReduction

source

PETSc.LibPETSc.KSPChebyshevEstEigGetKSP — Method

KSPChebyshevEstEigGetKSP(petsclib::PetscLibType,ksp::PetscKSP, kspest::PetscKSP)

Get the Krylov method context used to estimate the eigenvalues for the Chebyshev method.

Input Parameter:

ksp - the Krylov space context

Output Parameter:

kspest - the eigenvalue estimation Krylov space context

Level: advanced

-seealso: , KSPCHEBYSHEV, KSPChebyshevEstEigSet()

External Links

PETSc Manual: KSP/KSPChebyshevEstEigGetKSP

source

PETSc.LibPETSc.KSPChebyshevEstEigSet — Method

KSPChebyshevEstEigSet(petsclib::PetscLibType,ksp::PetscKSP, a::PetscReal, b::PetscReal, c::PetscReal, d::PetscReal)

Automatically estimate the eigenvalues to use for Chebyshev

Logically Collective

Input Parameters:

ksp - the Krylov space context
a - multiple of min eigenvalue estimate to use for min Chebyshev bound (or PETSC_DECIDE)
b - multiple of max eigenvalue estimate to use for min Chebyshev bound (or PETSC_DECIDE)
c - multiple of min eigenvalue estimate to use for max Chebyshev bound (or PETSC_DECIDE)
d - multiple of max eigenvalue estimate to use for max Chebyshev bound (or PETSC_DECIDE)

Options Database Key:

-ksp_chebyshev_esteig a,b,c,d - estimate eigenvalues using a Krylov method, then use this transform for Chebyshev eigenvalue bounds

-seealso: , KSPCHEBYSHEV, KSPChebyshevEstEigSetUseNoisy(), KSPChebyshevEstEigGetKSP()

External Links

PETSc Manual: KSP/KSPChebyshevEstEigSet

source

PETSc.LibPETSc.KSPChebyshevEstEigSetUseNoisy — Method

KSPChebyshevEstEigSetUseNoisy(petsclib::PetscLibType,ksp::PetscKSP, use::PetscBool)

use a noisy random number generated right

Logically Collective

Input Parameters:

ksp - linear solver context
use - PETSC_TRUE to use noisy

Options Database Key:

-ksp_chebyshev_esteig_noisy <true,false> - Use noisy right-hand side for estimate

Level: intermediate

-seealso: , KSPCHEBYSHEV, KSPChebyshevEstEigSet(), KSPChebyshevEstEigGetKSP()

External Links

PETSc Manual: KSP/KSPChebyshevEstEigSetUseNoisy

source

PETSc.LibPETSc.KSPChebyshevGetKind — Method

KSPChebyshevGetKind(petsclib::PetscLibType,ksp::PetscKSP, kind::KSPChebyshevKind)

get the kind of Chebyshev polynomial to use

Logically Collective

Input Parameters:

ksp - Linear solver context
kind - The kind of Chebyshev polynomial used

Level: intermediate

-seealso: , KSPCHEBYSHEV, KSPChebyshevKind, KSPChebyshevSetKind(), KSP_CHEBYSHEV_FIRST, KSP_CHEBYSHEV_FOURTH, KSP_CHEBYSHEV_OPT_FOURTH

External Links

PETSc Manual: KSP/KSPChebyshevGetKind

source

PETSc.LibPETSc.KSPChebyshevSetEigenvalues — Method

KSPChebyshevSetEigenvalues(petsclib::PetscLibType,ksp::PetscKSP, emax::PetscReal, emin::PetscReal)

Sets estimates for the extreme eigenvalues of the preconditioned problem.

Logically Collective

Input Parameters:

ksp - the Krylov space context
emax - the eigenvalue maximum estimate
emin - the eigenvalue minimum estimate

Options Database Key:

-ksp_chebyshev_eigenvalues emin,emax - extreme eigenvalues

Level: intermediate

-seealso: , KSPCHEBYSHEV, KSPChebyshevEstEigSet(),

External Links

PETSc Manual: KSP/KSPChebyshevSetEigenvalues

source

PETSc.LibPETSc.KSPChebyshevSetKind — Method

KSPChebyshevSetKind(petsclib::PetscLibType,ksp::PetscKSP, kind::KSPChebyshevKind)

set the kind of Chebyshev polynomial to use

Logically Collective

Input Parameters:

ksp - Linear solver context
kind - The kind of Chebyshev polynomial to use, see KSPChebyshevKind, one of KSP_CHEBYSHEV_FIRST, KSP_CHEBYSHEV_FOURTH, or KSP_CHEBYSHEV_OPT_FOURTH

Options Database Key:

-ksp_chebyshev_kind <kind> - which kind of Chebyshev polynomial to use

Level: intermediate

-seealso: , KSPCHEBYSHEV, KSPChebyshevKind, KSPChebyshevGetKind(), KSP_CHEBYSHEV_FIRST, KSP_CHEBYSHEV_FOURTH, KSP_CHEBYSHEV_OPT_FOURTH

External Links

PETSc Manual: KSP/KSPChebyshevSetKind

source

PETSc.LibPETSc.KSPCheckSolve — Method

KSPCheckSolve(petsclib::PetscLibType,ksp::PetscKSP, pc::PC, vec::PetscVec)

Checks if the PCSetUp() or KSPSolve() failed and set the error flag for the outer PC. A KSP_DIVERGED_ITS is not considered a failure in this context

Collective

Input Parameters:

ksp - the linear solver KSP context.
pc - the preconditioner context
vec - a vector that will be initialized with Inf to indicate lack of convergence

Level: developer

-seealso: , KSP, KSPCreate(), KSPSetType(), KSPCheckNorm(), KSPCheckDot()

External Links

PETSc Manual: KSP/KSPCheckSolve

source

PETSc.LibPETSc.KSPComputeConvergenceRate — Method

cr::PetscReal,rRsq::PetscReal,ce::PetscReal,eRsq::PetscReal = KSPComputeConvergenceRate(petsclib::PetscLibType,ksp::PetscKSP)

Compute the convergence rate for the iteration <https:/en.wikipedia.org/wiki/Coefficientofdetermination>

Not Collective

Input Parameter:

ksp - The KSP

Output Parameters:

cr - The residual contraction rate
rRsq - The coefficient of determination, R^2, indicating the linearity of the data
ce - The error contraction rate
eRsq - The coefficient of determination, R^2, indicating the linearity of the data

Level: advanced

-seealso: , KSP, KSPConvergedRateView()

External Links

PETSc Manual: KSP/KSPComputeConvergenceRate

source

PETSc.LibPETSc.KSPComputeEigenvalues — Method

r::Vector{PetscReal},c::Vector{PetscReal},neig::PetscInt = KSPComputeEigenvalues(petsclib::PetscLibType,ksp::PetscKSP, n::PetscInt)

Computes the extreme eigenvalues for the preconditioned operator. Called after or during KSPSolve().

Not Collective

Input Parameters:

ksp - iterative solver obtained from KSPCreate()
n - size of arrays r and c. The number of eigenvalues computed neig will, in general, be less than this.

Output Parameters:

r - real part of computed eigenvalues, provided by user with a dimension of at least n
c - complex part of computed eigenvalues, provided by user with a dimension of at least n
neig - actual number of eigenvalues computed (will be less than or equal to n)

Options Database Key:

-ksp_view_eigenvalues - Prints eigenvalues to stdout

Level: advanced

-seealso: , KSPSetComputeEigenvalues(), KSPSetComputeSingularValues(), KSPMonitorSingularValue(), KSPComputeExtremeSingularValues(), KSP, KSPComputeRitz()

External Links

PETSc Manual: KSP/KSPComputeEigenvalues

source

PETSc.LibPETSc.KSPComputeEigenvaluesExplicitly — Method

r::Vector{PetscReal},c::Vector{PetscReal} = KSPComputeEigenvaluesExplicitly(petsclib::PetscLibType,ksp::PetscKSP, nmax::PetscInt)

Computes all of the eigenvalues of the preconditioned operator using LAPACK.

Collective

Input Parameters:

ksp - iterative context obtained from KSPCreate()
nmax - size of arrays r and c

Output Parameters:

r - real part of computed eigenvalues, provided by user with a dimension at least of n
c - complex part of computed eigenvalues, provided by user with a dimension at least of n

Level: advanced

-seealso: , KSP, KSPComputeEigenvalues(), KSPMonitorSingularValue(), KSPComputeExtremeSingularValues(), KSPSetOperators(), KSPSolve()

External Links

PETSc Manual: KSP/KSPComputeEigenvaluesExplicitly

source

PETSc.LibPETSc.KSPComputeExtremeSingularValues — Method

emax::PetscReal,emin::PetscReal = KSPComputeExtremeSingularValues(petsclib::PetscLibType,ksp::PetscKSP)

Computes the extreme singular values for the preconditioned operator. Called after or during KSPSolve().

Not Collective

Input Parameter:

ksp - iterative solver obtained from KSPCreate()

Output Parameters:

emax - maximum estimated singular value
emin - minimum estimated singular value

Options Database Key:

-ksp_view_singularvalues - compute extreme singular values and print when KSPSolve() completes.

Level: advanced

-seealso: , KSPSetComputeSingularValues(), KSPMonitorSingularValue(), KSPComputeEigenvalues(), KSP, KSPComputeRitz()

External Links

PETSc Manual: KSP/KSPComputeExtremeSingularValues

source

PETSc.LibPETSc.KSPComputeOperator — Method

KSPComputeOperator(petsclib::PetscLibType,ksp::PetscKSP, mattype::MatType, mat::PetscMat)

Computes the explicit preconditioned operator, including diagonal scaling and null space removal if applicable.

Collective

Input Parameters:

ksp - the Krylov subspace context
mattype - the matrix type to be used

Output Parameter:

mat - the explicit preconditioned operator

Level: advanced

-seealso: , KSP, KSPSetOperators(), KSPComputeEigenvaluesExplicitly(), PCComputeOperator(), KSPSetDiagonalScale(), KSPSetNullSpace(), MatType

External Links

PETSc Manual: KSP/KSPComputeOperator

source

PETSc.LibPETSc.KSPComputeRitz — Method

nrit::PetscInt,tetar::Vector{PetscReal},tetai::Vector{PetscReal} = KSPComputeRitz(petsclib::PetscLibType,ksp::PetscKSP, ritz::PetscBool, small::PetscBool, S::Vector{PetscVec})

Computes the Ritz or harmonic Ritz pairs associated with the smallest or largest in modulus, for the preconditioned operator.

Not Collective

Input Parameters:

ksp - iterative solver obtained from KSPCreate()
ritz - PETSC_TRUE or PETSC_FALSE for Ritz pairs or harmonic Ritz pairs, respectively
small - PETSC_TRUE or PETSC_FALSE for smallest or largest (harmonic) Ritz values, respectively

Output Parameters:

nrit - On input number of (harmonic) Ritz pairs to compute; on output, actual number of computed (harmonic) Ritz pairs
S - an array of the Ritz vectors, pass in an array of vectors of size nrit
tetar - real part of the Ritz values, pass in an array of size nrit
tetai - imaginary part of the Ritz values, pass in an array of size nrit

Level: advanced

-seealso: , KSPSetComputeRitz(), KSP, KSPGMRES, KSPComputeEigenvalues(), KSPSetComputeSingularValues(), KSPMonitorSingularValue()

External Links

PETSc Manual: KSP/KSPComputeRitz

source

PETSc.LibPETSc.KSPConvergedDefault — Method

KSPConvergedDefault(petsclib::PetscLibType,ksp::PetscKSP, n::PetscInt, rnorm::PetscReal, reason::KSPConvergedReason, ctx::Cvoid)

Default code to determine convergence of the linear iterative solvers

Collective

Input Parameters:

ksp - iterative context
n - iteration number
rnorm - residual norm (may be estimated, depending on the method may be the preconditioned residual norm)
ctx - convergence context which must be created by KSPConvergedDefaultCreate()

Output Parameter:

reason - the convergence reason; it is positive if the iteration has converged,

negative if the iteration has diverged, and KSP_CONVERGED_ITERATING otherwise

Options Database Keys:

-ksp_max_it - maximum number of linear iterations
-ksp_min_it - minimum number of linear iterations, defaults to 0
-ksp_rtol rtol - relative tolerance used in default determination of convergence, i.e. if residual norm decreases by this factor than convergence is declared
-ksp_atol abstol - absolute tolerance used in default convergence test, i.e. if residual norm is less than this then convergence is declared
-ksp_divtol tol - if residual norm increases by this factor than divergence is declared
-ksp_converged_use_initial_residual_norm - see KSPConvergedDefaultSetUIRNorm()
-ksp_converged_use_min_initial_residual_norm - see KSPConvergedDefaultSetUMIRNorm()
-ksp_converged_maxits - see KSPConvergedDefaultSetConvergedMaxits()

Level: advanced

-seealso: , KSP, KSPSetConvergenceTest(), KSPSetTolerances(), KSPConvergedSkip(), KSPConvergedReason, KSPGetConvergedReason(), KSPSetMinimumIterations(), KSPConvergenceTestFn, KSPConvergedDefaultSetUIRNorm(), KSPConvergedDefaultSetUMIRNorm(), KSPConvergedDefaultSetConvergedMaxits(), KSPConvergedDefaultCreate(), KSPConvergedDefaultDestroy()

External Links

PETSc Manual: KSP/KSPConvergedDefault

source

PETSc.LibPETSc.KSPConvergedDefaultCreate — Method

ctx::Cvoid = KSPConvergedDefaultCreate(petsclib::PetscLibType)

Creates and initializes the context used by the KSPConvergedDefault() function

Not Collective

Output Parameter:

ctx - convergence context

Level: intermediate

-seealso: , KSP, KSPConvergedDefault(), KSPConvergedDefaultDestroy(), KSPSetConvergenceTest(), KSPSetTolerances(), KSPConvergedSkip(), KSPConvergedReason, KSPGetConvergedReason(), KSPConvergedDefaultSetUIRNorm(), KSPConvergedDefaultSetUMIRNorm(), KSPConvergedDefaultSetConvergedMaxits()

External Links

PETSc Manual: KSP/KSPConvergedDefaultCreate

source

PETSc.LibPETSc.KSPConvergedDefaultDestroy — Method

KSPConvergedDefaultDestroy(petsclib::PetscLibType,ctx::Cvoid)

Frees the space used by the KSPConvergedDefault() function context

Not Collective

Input Parameter:

ctx - convergence context

Level: intermediate

-seealso: , KSP, KSPConvergedDefault(), KSPConvergedDefaultCreate(), KSPSetConvergenceTest(), KSPSetTolerances(), KSPConvergedSkip(), KSPConvergedReason, KSPGetConvergedReason(), KSPConvergedDefaultSetUIRNorm(), KSPConvergedDefaultSetUMIRNorm()

External Links

PETSc Manual: KSP/KSPConvergedDefaultDestroy

source

PETSc.LibPETSc.KSPConvergedDefaultSetConvergedMaxits — Method

KSPConvergedDefaultSetConvergedMaxits(petsclib::PetscLibType,ksp::PetscKSP, flg::PetscBool)

allows the default convergence test to declare convergence and return KSP_CONVERGED_ITS if the maximum number of iterations is reached

Collective

Input Parameters:

ksp - iterative context
flg - boolean flag

Options Database Key:

-ksp_converged_maxits <bool> - Declare convergence if the maximum number of iterations is reached

Level: intermediate

-seealso: , KSP, KSPSetConvergenceTest(), KSPSetTolerances(), KSPConvergedSkip(), KSPConvergedReason, KSPGetConvergedReason(), KSPConvergedDefaultSetUMIRNorm(), KSPConvergedDefaultSetUIRNorm()

External Links

PETSc Manual: KSP/KSPConvergedDefaultSetConvergedMaxits

source

PETSc.LibPETSc.KSPConvergedDefaultSetUIRNorm — Method

KSPConvergedDefaultSetUIRNorm(petsclib::PetscLibType,ksp::PetscKSP)

makes the default convergence test use || B(b instead of || Bb ||. In the case of right preconditioner or if KSPSetNormType(ksp,KSP_NORM_UNPRECONDITIONED) is used there is no B in the above formula.

Collective

Input Parameters:

ksp - iterative context

Options Database Key:

-ksp_converged_use_initial_residual_norm <bool> - Use initial residual norm for computing relative convergence

Level: intermediate

External Links

PETSc Manual: KSP/KSPConvergedDefaultSetUIRNorm

source

PETSc.LibPETSc.KSPConvergedDefaultSetUMIRNorm — Method

KSPConvergedDefaultSetUMIRNorm(petsclib::PetscLibType,ksp::PetscKSP)

makes the default convergence test use min(|| B*(b In the case of right preconditioner or if KSPSetNormType(ksp,KSP_NORM_UNPRECONDITIONED) is used there is no B in the above formula.

Collective

Input Parameters:

ksp - iterative context

Options Database Key:

-ksp_converged_use_min_initial_residual_norm <bool> - Use minimum of initial residual norm and b for computing relative convergence

Level: intermediate

External Links

PETSc Manual: KSP/KSPConvergedDefaultSetUMIRNorm

source

PETSc.LibPETSc.KSPConvergedRateView — Method

KSPConvergedRateView(petsclib::PetscLibType,ksp::PetscKSP, viewer::PetscViewer)

Displays the convergence rate https://en.wikipedia.org/wiki/Coefficient_of_determination of KSPSolve() to a viewer

Collective

Input Parameters:

ksp - iterative solver obtained from KSPCreate()
viewer - the PetscViewer to display the reason

Options Database Key:

-ksp_converged_rate - print reason for convergence or divergence and the convergence rate (or 0.0 for divergence)

Level: intermediate

-seealso: , KSPConvergedReasonView(), KSPGetConvergedRate(), KSPSetTolerances(), KSPConvergedDefault()

External Links

PETSc Manual: KSP/KSPConvergedRateView

source

PETSc.LibPETSc.KSPConvergedReasonView — Method

KSPConvergedReasonView(petsclib::PetscLibType,ksp::PetscKSP, viewer::PetscViewer)

Displays the reason a KSP solve converged or diverged, KSPConvergedReason to a PetscViewer

Collective

Input Parameters:

ksp - iterative solver obtained from KSPCreate()
viewer - the PetscViewer on which to display the reason

Options Database Keys:

-ksp_converged_reason - print reason for converged or diverged, also prints number of iterations
-ksp_converged_reason ::failed - only print reason and number of iterations when diverged

Level: beginner

-seealso: , KSPConvergedReasonViewFromOptions(), KSPCreate(), KSPSetUp(), KSPDestroy(), KSPSetTolerances(), KSPConvergedDefault(), KSPSolveTranspose(), KSPGetIterationNumber(), KSP, KSPGetConvergedReason(), PetscViewerPushFormat(), PetscViewerPopFormat()

External Links

PETSc Manual: KSP/KSPConvergedReasonView

source

PETSc.LibPETSc.KSPConvergedReasonViewCancel — Method

KSPConvergedReasonViewCancel(petsclib::PetscLibType,ksp::PetscKSP)

Clears all the KSPConvergedReason view functions for a KSP object set with KSPConvergedReasonViewSet() as well as the default viewer.

Collective

Input Parameter:

ksp - iterative solver obtained from KSPCreate()

Level: intermediate

-seealso: , KSPCreate(), KSPDestroy(), KSPReset(), KSPConvergedReasonViewSet()

External Links

PETSc Manual: KSP/KSPConvergedReasonViewCancel

source

PETSc.LibPETSc.KSPConvergedReasonViewFromOptions — Method

KSPConvergedReasonViewFromOptions(petsclib::PetscLibType,ksp::PetscKSP)

Processes command line options to determine if/how a KSPReason is to be viewed.

Collective

Input Parameter:

ksp - the KSP object

Level: intermediate

-seealso: , KSPConvergedReasonView(), KSPConvergedReasonViewSet()

External Links

PETSc Manual: KSP/KSPConvergedReasonViewFromOptions

source

PETSc.LibPETSc.KSPConvergedReasonViewSet — Method

KSPConvergedReasonViewSet(petsclib::PetscLibType,ksp::PetscKSP, f::KSPConvergedReasonViewFn, vctx::Cvoid, reasonviewdestroy::PetscCtxDestroyFn)

Sets an ADDITIONAL function that is to be used at the end of the linear solver to display the convergence reason of the linear solver.

Logically Collective

Input Parameters:

ksp - the KSP context
f - the ksp converged reason view function, see KSPConvergedReasonViewFn
vctx - [optional] user-defined context for private data for the

KSPConvergedReason view routine (use NULL if no context is desired)

reasonviewdestroy - [optional] routine that frees vctx (may be NULL), see PetscCtxDestroyFn for the calling sequence

Options Database Keys:

-ksp_converged_reason - sets a default KSPConvergedReasonView()
-ksp_converged_reason_view_cancel - cancels all converged reason viewers that have been hardwired into a code by

calls to KSPConvergedReasonViewSet(), but does not cancel those set via the options database.

Level: intermediate

-seealso: , KSPConvergedReasonView(), KSPConvergedReasonViewFn, KSPConvergedReasonViewCancel(), PetscCtxDestroyFn

External Links

PETSc Manual: KSP/KSPConvergedReasonViewSet

source

PETSc.LibPETSc.KSPConvergedSkip — Method

KSPConvergedSkip(petsclib::PetscLibType,ksp::PetscKSP, n::PetscInt, rnorm::PetscReal, reason::KSPConvergedReason, dtx::Cvoid)

Convergence test that do not return as converged until the maximum number of iterations is reached.

Collective

Input Parameters:

ksp - iterative context
n - iteration number
rnorm - 2-norm residual value (may be estimated)
dtx - unused convergence context

Output Parameter:

reason - KSP_CONVERGED_ITERATING or KSP_CONVERGED_ITS

Options Database Key:

-ksp_convergence_test skip - skips the test

Level: advanced

-seealso: , KSP, KSPCG, KSPBCGS, KSPConvergenceTestFn, KSPSetConvergenceTest(), KSPSetTolerances(), KSPSetNormType(), , KSPConvergedReason

External Links

PETSc Manual: KSP/KSPConvergedSkip

source

PETSc.LibPETSc.KSPCreate — Method

inksp::PetscKSP = KSPCreate(petsclib::PetscLibType,comm::MPI_Comm)

Creates the KSP context. This KSP context is used in PETSc to solve linear systems with KSPSolve()

Collective

Input Parameter:

comm - MPI communicator

Output Parameter:

inksp - location to put the KSP context

Level: beginner

-seealso: , KSPSetUp(), KSPSolve(), KSPDestroy(), KSP, KSPGMRES, KSPType, KSPSetType()

External Links

PETSc Manual: KSP/KSPCreate

source

PETSc.LibPETSc.KSPCreateVecs — Method

right::Vector{PetscVec},left::Vector{PetscVec} = KSPCreateVecs(petsclib::PetscLibType,ksp::PetscKSP, rightn::PetscInt, leftn::PetscInt)

Gets a number of work vectors suitably sized for the operator in the KSP

Collective

Input Parameters:

ksp - iterative context
rightn - number of right work vectors to allocate
leftn - number of left work vectors to allocate

Output Parameters:

right - the array of vectors created
left - the array of left vectors

Level: advanced

-seealso: , MatCreateVecs(), VecDestroyVecs(), KSPSetWorkVecs()

External Links

PETSc Manual: KSP/KSPCreateVecs

source

PETSc.LibPETSc.KSPDestroy — Method

KSPDestroy(petsclib::PetscLibType,ksp::PetscKSP)

Destroys a KSP context.

Collective

Input Parameter:

ksp - iterative solver obtained from KSPCreate()

Level: beginner

-seealso: , KSPCreate(), KSPSetUp(), KSPSolve(), KSP

External Links

PETSc Manual: KSP/KSPDestroy

source

PETSc.LibPETSc.KSPDestroyDefault — Method

KSPDestroyDefault(petsclib::PetscLibType,ksp::PetscKSP)

External Links

PETSc Manual: KSP/KSPDestroyDefault

source

PETSc.LibPETSc.KSPFCGGetMmax — Method

mmax::PetscInt = KSPFCGGetMmax(petsclib::PetscLibType,ksp::PetscKSP)

get the maximum number of previous directions KSPFCG will store

Not Collective

Input Parameter:

ksp - the Krylov space context

Output Parameter:

mmax - the maximum number of previous directions allowed for orthogonalization

Level: intermediate

-seealso: , KSPFCG, KSPFCGGetTruncationType(), KSPFCGGetNprealloc(), KSPFCGSetMmax()

External Links

PETSc Manual: KSP/KSPFCGGetMmax

source

PETSc.LibPETSc.KSPFCGGetNprealloc — Method

nprealloc::PetscInt = KSPFCGGetNprealloc(petsclib::PetscLibType,ksp::PetscKSP)

get the number of directions preallocate by KSPFCG

Not Collective

Input Parameter:

ksp - the Krylov space context

Output Parameter:

nprealloc - the number of directions preallocated

Level: advanced

-seealso: , KSPFCG, KSPFCGGetTruncationType(), KSPFCGSetNprealloc(), KSPFCGSetMmax(), KSPFCGGetMmax()

External Links

PETSc Manual: KSP/KSPFCGGetNprealloc

source

PETSc.LibPETSc.KSPFCGGetTruncationType — Method

truncstrat::KSPFCDTruncationType = KSPFCGGetTruncationType(petsclib::PetscLibType,ksp::PetscKSP)

get the truncation strategy employed by KSPFCG

Not Collective

Input Parameter:

ksp - the Krylov space context

Output Parameter:

truncstrat - the strategy type

Level: intermediate

-seealso: , KSPFCG, KSPFCGSetTruncationType(), KSPFCDTruncationType, KSP_FCD_TRUNC_TYPE_STANDARD, KSP_FCD_TRUNC_TYPE_NOTAY

External Links

PETSc Manual: KSP/KSPFCGGetTruncationType

source

PETSc.LibPETSc.KSPFCGSetMmax — Method

KSPFCGSetMmax(petsclib::PetscLibType,ksp::PetscKSP, mmax::PetscInt)

set the maximum number of previous directions KSPFCG will store for orthogonalization

Logically Collective

Input Parameters:

ksp - the Krylov space context
mmax - the maximum number of previous directions to orthogonalize against

Options Database Key:

-ksp_fcg_mmax <N> - maximum number of search directions

Level: intermediate

-seealso: , KSPFCG, KSPFCGGetTruncationType(), KSPFCGGetNprealloc(), KSPFCGetMmax()

External Links

PETSc Manual: KSP/KSPFCGSetMmax

source

PETSc.LibPETSc.KSPFCGSetNprealloc — Method

KSPFCGSetNprealloc(petsclib::PetscLibType,ksp::PetscKSP, nprealloc::PetscInt)

set the number of directions to preallocate with KSPFCG

Logically Collective

Input Parameters:

ksp - the Krylov space context
nprealloc - the number of vectors to preallocate

Options Database Key:

-ksp_fcg_nprealloc <N> - number of directions to preallocate

Level: advanced

-seealso: , KSPFCG, KSPFCGGetTruncationType(), KSPFCGGetNprealloc(), KSPFCGSetMmax(), KSPFCGGetMmax()

External Links

PETSc Manual: KSP/KSPFCGSetNprealloc

source

PETSc.LibPETSc.KSPFCGSetTruncationType — Method

KSPFCGSetTruncationType(petsclib::PetscLibType,ksp::PetscKSP, truncstrat::KSPFCDTruncationType)

specify how many of its stored previous directions KSPFCG uses during orthoganalization

Logically Collective

Input Parameters:

ksp - the Krylov space context
truncstrat - the choice of strategy

-seealso: , KSPFCDTruncationType, KSPFCGGetTruncationType(), KSPFCGSetNprealloc(), KSPFCGSetMmax(), KSPFCGGetMmax(), KSP_FCD_TRUNC_TYPE_STANDARD, KSP_FCD_TRUNC_TYPE_NOTAY

External Links

PETSc Manual: KSP/KSPFCGSetTruncationType

source

PETSc.LibPETSc.KSPFETIDPGetInnerBDDC — Method

KSPFETIDPGetInnerBDDC(petsclib::PetscLibType,ksp::PetscKSP, pc::PC)

Gets the PCBDDC preconditioner used to set up the KSPFETIDP matrix for the Lagrange multipliers

Input Parameter:

ksp - the KSPFETIDP Krylov solver

Output Parameter:

pc - the PCBDDC preconditioner

Level: advanced

-seealso: , MATIS, PCBDDC, KSPFETIDP, KSPFETIDPSetInnerBDDC(), KSPFETIDPGetInnerKSP()

External Links

PETSc Manual: KSP/KSPFETIDPGetInnerBDDC

source

PETSc.LibPETSc.KSPFETIDPGetInnerKSP — Method

KSPFETIDPGetInnerKSP(petsclib::PetscLibType,ksp::PetscKSP, innerksp::PetscKSP)

Gets the KSP object for the Lagrange multipliers from inside a KSPFETIDP

Input Parameter:

ksp - the KSPFETIDP

Output Parameter:

innerksp - the KSP for the multipliers

Level: advanced

-seealso: , KSPFETIDP, MATIS, PCBDDC, KSPFETIDPSetInnerBDDC(), KSPFETIDPGetInnerBDDC()

External Links

PETSc Manual: KSP/KSPFETIDPGetInnerKSP

source

PETSc.LibPETSc.KSPFETIDPSetInnerBDDC — Method

KSPFETIDPSetInnerBDDC(petsclib::PetscLibType,ksp::PetscKSP, pc::PC)

Provides the PCBDDC preconditioner used to set up the KSPFETIDP matrix for the Lagrange multipliers

Collective

Input Parameters:

ksp - the KSPFETIDP Krylov solver
pc - the PCBDDC preconditioner

Level: advanced

-seealso: , MATIS, PCBDDC, KSPFETIDPGetInnerBDDC(), KSPFETIDPGetInnerKSP()

External Links

PETSc Manual: KSP/KSPFETIDPSetInnerBDDC

source

PETSc.LibPETSc.KSPFETIDPSetPressureOperator — Method

KSPFETIDPSetPressureOperator(petsclib::PetscLibType,ksp::PetscKSP, P::PetscMat)

Sets the operator used to set up the pressure preconditioner for the saddle point KSPFETIDP solver,

Collective

Input Parameters:

ksp - the KSPFETIDP solver
P - the linear operator to be preconditioned, usually the mass matrix.

Level: advanced

-seealso: , KSPFETIDP, MATIS, PCBDDC, KSPFETIDPGetInnerBDDC(), KSPFETIDPGetInnerKSP(), KSPSetOperators()

External Links

PETSc Manual: KSP/KSPFETIDPSetPressureOperator

source

PETSc.LibPETSc.KSPFGMRESModifyPCKSP — Method

KSPFGMRESModifyPCKSP(petsclib::PetscLibType,ksp::PetscKSP, total_its::PetscInt, loc_its::PetscInt, res_norm::PetscReal, ctx::Cvoid)

modifies the attributes of the KSPFGMRES preconditioner, see .

Input Parameters:

ksp - the ksp context being used.
total_its - the total number of KSPFGMRES iterations that have occurred.
loc_its - the number of KSPFGMRES iterations since last restart.
res_norm - the current residual norm.
ctx - context, not used in this routine

Level: intermediate

-seealso: , , KSPFGMRES, KSPFlexibleModifyPCFn, KSPFGMRESSetModifyPC()

External Links

PETSc Manual: KSP/KSPFGMRESModifyPCKSP

source

PETSc.LibPETSc.KSPFGMRESModifyPCNoChange — Method

KSPFGMRESModifyPCNoChange(petsclib::PetscLibType,ksp::PetscKSP, total_its::PetscInt, loc_its::PetscInt, res_norm::PetscReal, ctx::Cvoid)

this is the default used by KSPFMGMRES

Input Parameters:

ksp - the ksp context being used.
total_its - the total number of KSPFGMRES iterations that have occurred.
loc_its - the number of KSPFGMRES iterations since last restart.
res_norm - the current residual norm.
ctx - context variable, unused in this routine

Level: intermediate

-seealso: , , KSPFGMRES, KSPFlexibleModifyPCFn, KSPFGMRESSetModifyPC(), KSPFGMRESModifyPCKSP()

External Links

PETSc Manual: KSP/KSPFGMRESModifyPCNoChange

source

PETSc.LibPETSc.KSPFGMRESSetModifyPC — Method

KSPFGMRESSetModifyPC(petsclib::PetscLibType,ksp::PetscKSP, fcn::KSPFlexibleModifyPCFn, ctx::Cvoid, destroy::PetscCtxDestroyFn)

Sets the routine used by KSPFGMRES to modify the preconditioner.

Logically Collective

Input Parameters:

ksp - iterative context obtained from KSPCreate()
fcn - function to modify the PC, see KSPFlexibleModifyPCFn
ctx - optional context
destroy - optional context destroy routine

Options Database Keys:

-ksp_fgmres_modifypcnochange - do not change the PC
-ksp_fgmres_modifypcksp - changes the inner KSP solver tolerances

Level: intermediate

-seealso: , , KSPFGMRES, KSPFlexibleModifyPCFn, KSPFlexibleSetModifyPC(), KSPFGMRESModifyPCNoChange(), KSPFGMRESModifyPCKSP()

External Links

PETSc Manual: KSP/KSPFGMRESSetModifyPC

source

PETSc.LibPETSc.KSPFinalizePackage — Method

KSPFinalizePackage(petsclib::PetscLibType)

This function destroys everything in the KSP package. It is called from PetscFinalize().

Level: developer

-seealso: , PetscFinalize(), KSPInitializePackage()

External Links

PETSc Manual: KSP/KSPFinalizePackage

source

PETSc.LibPETSc.KSPFlexibleSetModifyPC — Method

KSPFlexibleSetModifyPC(petsclib::PetscLibType,ksp::PetscKSP, fcn::KSPFlexibleModifyPCFn, ctx::Cvoid, destroy::PetscCtxDestroyFn)

Sets the routine used by flexible KSP methods to modify the preconditioner.

Logically Collective

Input Parameters:

ksp - iterative context obtained from KSPCreate()
fcn - function to modify the PC, see KSPFlexibleModifyPCFn
ctx - optional context
destroy - optional context destroy routine

Level: intermediate

-seealso: , , KSPFGMRES, KSPFGMRESModifyPCNoChange(), KSPFGMRESModifyPCKSP()

External Links

PETSc Manual: KSP/KSPFlexibleSetModifyPC

source

PETSc.LibPETSc.KSPGCRGetRestart — Method

restart::PetscInt = KSPGCRGetRestart(petsclib::PetscLibType,ksp::PetscKSP)

Gets number of iterations at which KSPGCR restarts.

Not Collective

Input Parameter:

ksp - the Krylov space context

Output Parameter:

restart - integer restart value

Level: intermediate

-seealso: , KSPGCR, KSPSetTolerances(), KSPGCRSetRestart(), KSPGMRESGetRestart()

External Links

PETSc Manual: KSP/KSPGCRGetRestart

source

PETSc.LibPETSc.KSPGCRSetModifyPC — Method

KSPGCRSetModifyPC(petsclib::PetscLibType,ksp::PetscKSP, fnc::KSPFlexibleModifyPCFn, ctx::Cvoid, destroy::PetscCtxDestroyFn)

Sets the routine used by KSPGCR to modify the preconditioner for each iteration

Logically Collective

Input Parameters:

ksp - iterative context obtained from KSPCreate()
function - user defined function to modify the preconditioner, see KSPFlexibleModifyPCFn
ctx - user provided context for the modify preconditioner function
destroy - the function to use to destroy the user provided application context.

Level: intermediate

-seealso: , KSP, KSPGCR, KSPFlexibleModifyPCFn, KSPFGMRESModifyPCFn,

External Links

PETSc Manual: KSP/KSPGCRSetModifyPC

source

PETSc.LibPETSc.KSPGCRSetRestart — Method

KSPGCRSetRestart(petsclib::PetscLibType,ksp::PetscKSP, restart::PetscInt)

Sets number of iterations at which KSPGCR restarts.

Not Collective

Input Parameters:

ksp - the Krylov space context
restart - integer restart value

Options Database Key:

-ksp_gcr_restart <restart> - the number of stored vectors to orthogonalize against

Level: intermediate

-seealso: , KSPGCR, KSPSetTolerances(), KSPGCRGetRestart(), KSPGMRESSetRestart()

External Links

PETSc Manual: KSP/KSPGCRSetRestart

source

PETSc.LibPETSc.KSPGLTRGetLambda — Method

lambda::PetscReal = KSPGLTRGetLambda(petsclib::PetscLibType,ksp::PetscKSP)

Get the multiplier on the trust

Not Collective

Input Parameter:

ksp - the iterative context

Output Parameter:

lambda - the multiplier

Level: advanced

-seealso: , KSP, KSPGLTR, KSPGLTRGetMinEig()

External Links

PETSc Manual: KSP/KSPGLTRGetLambda

source

PETSc.LibPETSc.KSPGLTRGetMinEig — Method

e_min::PetscReal = KSPGLTRGetMinEig(petsclib::PetscLibType,ksp::PetscKSP)

Get minimum eigenvalue computed by KSPGLTR

Collective

Input Parameter:

ksp - the iterative context

Output Parameter:

e_min - the minimum eigenvalue

Level: advanced

-seealso: , KSP, KSPGLTR, KSPGLTRGetLambda()

External Links

PETSc Manual: KSP/KSPGLTRGetMinEig

source

PETSc.LibPETSc.KSPGMRESClassicalGramSchmidtOrthogonalization — Method

KSPGMRESClassicalGramSchmidtOrthogonalization(petsclib::PetscLibType,ksp::PetscKSP, it::PetscInt)

This is the basic orthogonalization routine using classical Gram-Schmidt with possible iterative refinement to improve the stability

Collective, No Fortran Support

Input Parameters:

ksp - KSP object, must be associated with KSPGMRES, KSPFGMRES, or KSPLGMRES Krylov method
it - one less than the current GMRES restart iteration, i.e. the size of the Krylov space

Options Database Keys:

-ksp_gmres_classicalgramschmidt - Activates KSPGMRESClassicalGramSchmidtOrthogonalization()
-ksp_gmres_cgs_refinement_type <refine_never,refine_ifneeded,refine_always> - determine if iterative refinement is

used to increase the stability of the classical Gram-Schmidt orthogonalization.

Level: intermediate

-seealso: , KSPGMRESCGSRefinementType, KSPGMRESSetOrthogonalization(), KSPGMRESSetCGSRefinementType(), KSPGMRESGetCGSRefinementType(), KSPGMRESGetOrthogonalization(), KSPGMRESModifiedGramSchmidtOrthogonalization()

External Links

PETSc Manual: KSP/KSPGMRESClassicalGramSchmidtOrthogonalization

source

PETSc.LibPETSc.KSPGMRESGetCGSRefinementType — Method

type::KSPGMRESCGSRefinementType = KSPGMRESGetCGSRefinementType(petsclib::PetscLibType,ksp::PetscKSP)

Gets the type of iterative refinement to use in the classical Gram-Schmidt orthogonalization used by KSPGMRES and other PETSc GMRES implementations.

Not Collective

Input Parameter:

ksp - the Krylov space solver context

Output Parameter:

type - the type of refinement

Level: intermediate

-seealso: , KSPGMRES, KSPGMRESSetOrthogonalization(), KSPGMRESCGSRefinementType, KSPGMRESClassicalGramSchmidtOrthogonalization(), KSPGMRESSetCGSRefinementType(), KSPGMRESGetOrthogonalization()

External Links

PETSc Manual: KSP/KSPGMRESGetCGSRefinementType

source

PETSc.LibPETSc.KSPGMRESGetRestart — Method

restart::PetscInt = KSPGMRESGetRestart(petsclib::PetscLibType,ksp::PetscKSP)

Gets number of iterations at which GMRES (KSPGMRES, KSPFGMRES, KSPPGMRES, KSPAGMRES, KSPDGMRES, KSPPIPEFGMRES, and KSPLGMRES) restarts.

Not Collective

Input Parameter:

ksp - the Krylov space solver context

Output Parameter:

restart - integer restart value

Level: intermediate

-seealso: , KSPGMRES, KSPSetTolerances(), KSPGMRESSetOrthogonalization(), KSPGMRESSetPreAllocateVectors(), KSPGMRESSetRestart(), KSPFGMRES, KSPLGMRES, KSPPGMRES, KSPAGMRES, KSPDGMRES, KSPPIPEFGMRES

External Links

PETSc Manual: KSP/KSPGMRESGetRestart

source

PETSc.LibPETSc.KSPGMRESModifiedGramSchmidtOrthogonalization — Method

KSPGMRESModifiedGramSchmidtOrthogonalization(petsclib::PetscLibType,ksp::PetscKSP, it::PetscInt)

This is the basic orthogonalization routine using modified Gram-Schmidt.

Collective, No Fortran Support

Input Parameters:

ksp - KSP object, must be associated with KSPGMRES, KSPFGMRES, or KSPLGMRES Krylov method
it - one less than the current GMRES restart iteration, i.e. the size of the Krylov space

Options Database Key:

-ksp_gmres_modifiedgramschmidt - Activates KSPGMRESModifiedGramSchmidtOrthogonalization()

Level: intermediate

-seealso: , KSPGMRESSetOrthogonalization(), KSPGMRESClassicalGramSchmidtOrthogonalization(), KSPGMRESGetOrthogonalization()

External Links

PETSc Manual: KSP/KSPGMRESModifiedGramSchmidtOrthogonalization

source

PETSc.LibPETSc.KSPGMRESMonitorKrylov — Method

KSPGMRESMonitorKrylov(petsclib::PetscLibType,ksp::PetscKSP, its::PetscInt, fgnorm::PetscReal, dummy::Cvoid)

Calls VecView() to monitor each new direction in the KSPGMRES accumulated Krylov space.

Collective

Input Parameters:

ksp - the KSP context
its - iteration number
fgnorm - 2-norm of residual (or gradient)
dummy - a collection of viewers created with PetscViewersCreate()

Options Database Key:

-ksp_gmres_krylov_monitor <bool> - Plot the Krylov directions

Level: intermediate

-seealso: , KSPGMRES, KSPMonitorSet(), KSPMonitorResidual(), VecView(), PetscViewersCreate(), PetscViewersDestroy()

External Links

PETSc Manual: KSP/KSPGMRESMonitorKrylov

source

PETSc.LibPETSc.KSPGMRESSetBreakdownTolerance — Method

KSPGMRESSetBreakdownTolerance(petsclib::PetscLibType,ksp::PetscKSP, tol::PetscReal)

Sets the tolerance for determining divergence breakdown in KSPGMRES at restart.

Logically Collective

Input Parameters:

ksp - the Krylov space solver context
tol - the tolerance

Options Database Key:

-ksp_gmres_breakdown_tolerance <positive real value> - set tolerance for determining divergence breakdown

Level: intermediate

-seealso: , KSPGMRES, KSPSetTolerances(), KSPGMRESSetHapTol(), KSPConvergedReason

External Links

PETSc Manual: KSP/KSPGMRESSetBreakdownTolerance

source

PETSc.LibPETSc.KSPGMRESSetCGSRefinementType — Method

KSPGMRESSetCGSRefinementType(petsclib::PetscLibType,ksp::PetscKSP, type::KSPGMRESCGSRefinementType)

Sets the type of iterative refinement to use in the classical Gram-Schmidt orthogonalization used by KSPGMRES and other PETSc GMRES implementations.

Logically Collective

Input Parameters:

ksp - the Krylov space solver context
type - the type of refinement

-seealso: , KSPGMRES, KSPGMRESSetOrthogonalization(), KSPGMRESCGSRefinementType, KSPGMRESClassicalGramSchmidtOrthogonalization(), KSPGMRESGetCGSRefinementType(), KSPGMRESGetOrthogonalization()

External Links

PETSc Manual: KSP/KSPGMRESSetCGSRefinementType

source

PETSc.LibPETSc.KSPGMRESSetHapTol — Method

KSPGMRESSetHapTol(petsclib::PetscLibType,ksp::PetscKSP, tol::PetscReal)

Sets the tolerance for detecting a happy ending in GMRES (KSPGMRES, KSPFGMRES and KSPLGMRES and others)

Logically Collective

Input Parameters:

ksp - the Krylov space solver context
tol - the tolerance for detecting a happy ending

Options Database Key:

-ksp_gmres_haptol <positive real value> - set tolerance for determining happy breakdown

Level: intermediate

-seealso: , KSPGMRES, KSPSetTolerances()

External Links

PETSc Manual: KSP/KSPGMRESSetHapTol

source

PETSc.LibPETSc.KSPGMRESSetOrthogonalization — Method

KSPGMRESSetOrthogonalization(petsclib::PetscLibType,ksp::PetscKSP, fcn::external)

Sets the orthogonalization routine used by KSPGMRES and KSPFGMRES.

Logically Collective

Input Parameters:

ksp - iterative context obtained from KSPCreate()
fcn - orthogonalization function

Calling sequence of fcn:

ksp - the solver context
it - the current iteration

Options Database Keys:

-ksp_gmres_classicalgramschmidt - Activates KSPGMRESClassicalGramSchmidtOrthogonalization() (default)
-ksp_gmres_modifiedgramschmidt - Activates KSPGMRESModifiedGramSchmidtOrthogonalization()

Level: intermediate

-seealso: , KSPGMRESSetRestart(), KSPGMRESSetPreAllocateVectors(), KSPGMRESSetCGSRefinementType(), KSPGMRESModifiedGramSchmidtOrthogonalization(), KSPGMRESClassicalGramSchmidtOrthogonalization(), KSPGMRESGetCGSRefinementType()

External Links

PETSc Manual: KSP/KSPGMRESSetOrthogonalization

source

PETSc.LibPETSc.KSPGMRESSetPreAllocateVectors — Method

KSPGMRESSetPreAllocateVectors(petsclib::PetscLibType,ksp::PetscKSP)

Causes KSPGMRES and KSPFGMRES to preallocate all its needed work vectors at initial setup rather than the default, which is to allocate several at a time when needed.

Logically Collective

Input Parameter:

ksp - iterative context obtained from KSPCreate()

Options Database Key:

-ksp_gmres_preallocate - Activates KSPGmresSetPreAllocateVectors()

Level: intermediate

-seealso: , KSPGMRESSetRestart(), KSPGMRESSetOrthogonalization(), KSPGMRESGetOrthogonalization(), VecMDot(), VecMAXPY()

External Links

PETSc Manual: KSP/KSPGMRESSetPreAllocateVectors

source

PETSc.LibPETSc.KSPGMRESSetRestart — Method

KSPGMRESSetRestart(petsclib::PetscLibType,ksp::PetscKSP, restart::PetscInt)

Sets number of iterations at which GMRES (KSPGMRES, KSPFGMRES, KSPPGMRES, KSPAGMRES, KSPDGMRES, KSPPIPEFGMRES, and KSPLGMRES) restarts.

Logically Collective

Input Parameters:

ksp - the Krylov space solver context
restart - integer restart value, this corresponds to the number of iterations of GMRES to perform before restarting

Options Database Key:

-ksp_gmres_restart <positive integer> - integer restart value

Level: intermediate

-seealso: , KSPGMRES, KSPSetTolerances(), KSPGMRESSetOrthogonalization(), KSPGMRESSetPreAllocateVectors(), KSPGMRESGetRestart(), KSPFGMRES, KSPLGMRES, KSPPGMRES, KSPAGMRES, KSPDGMRES, KSPPIPEFGMRES

External Links

PETSc Manual: KSP/KSPGMRESSetRestart

source

PETSc.LibPETSc.KSPGetAndClearConvergenceTest — Method

KSPGetAndClearConvergenceTest(petsclib::PetscLibType,ksp::PetscKSP, converge::KSPConvergenceTestFn, ctx::Cvoid, destroy::PetscCtxDestroyFn)

Gets the function to be used to determine convergence. Removes the current test without calling destroy on the test context

Logically Collective

Input Parameter:

ksp - iterative solver obtained from KSPCreate()

Output Parameters:

converge - pointer to convergence test function, see KSPConvergenceTestFn
ctx - context for private data for the convergence routine
destroy - a routine for destroying the context

Level: advanced

-seealso: , KSP, KSPConvergedDefault(), KSPGetConvergenceContext(), KSPSetTolerances(), KSPSetConvergenceTest(), KSPGetConvergenceTest()

External Links

PETSc Manual: KSP/KSPGetAndClearConvergenceTest

source

PETSc.LibPETSc.KSPGetApplicationContext — Method

KSPGetApplicationContext(petsclib::PetscLibType,ksp::PetscKSP, ctx::PeCtx)

Gets the user

Not Collective

Input Parameter:

ksp - KSP context

Output Parameter:

ctx - a pointer to the user context

Level: intermediate

-seealso: , KSP, KSPSetApplicationContext()

External Links

PETSc Manual: KSP/KSPGetApplicationContext

source

PETSc.LibPETSc.KSPGetComputeEigenvalues — Method

flg::PetscBool = KSPGetComputeEigenvalues(petsclib::PetscLibType,ksp::PetscKSP)

Gets the flag indicating that the extreme eigenvalues values will be calculated via a Lanczos or Arnoldi process as the linear system is solved.

Not Collective

Input Parameter:

ksp - iterative solver obtained from KSPCreate()

Output Parameter:

flg - PETSC_TRUE or PETSC_FALSE

Level: advanced

-seealso: , KSPComputeEigenvalues(), KSPComputeEigenvaluesExplicitly(), KSP, KSPSetComputeRitz()

External Links

PETSc Manual: KSP/KSPGetComputeEigenvalues

source

PETSc.LibPETSc.KSPGetComputeSingularValues — Method

flg::PetscBool = KSPGetComputeSingularValues(petsclib::PetscLibType,ksp::PetscKSP)

Gets the flag indicating whether the extreme singular values will be calculated via a Lanczos or Arnoldi process as the linear system is solved.

Not Collective

Input Parameter:

ksp - iterative solver obtained from KSPCreate()

Output Parameter:

flg - PETSC_TRUE or PETSC_FALSE

Options Database Key:

-ksp_monitor_singular_value - Activates KSPSetComputeSingularValues()

Level: advanced

-seealso: , KSPComputeExtremeSingularValues(), KSPMonitorSingularValue(), KSP

External Links

PETSc Manual: KSP/KSPGetComputeSingularValues

source

PETSc.LibPETSc.KSPGetConvergedNegativeCurvature — Method

flg::PetscBool = KSPGetConvergedNegativeCurvature(petsclib::PetscLibType,ksp::PetscKSP)

Get the flag to declare convergence if negative curvature is detected

Collective

Input Parameter:

ksp - iterative context

Output Parameter:

flg - the Boolean value

Level: advanced

-seealso: , KSP, KSPConvergedReason, KSPSetConvergedNegativeCurvature()

External Links

PETSc Manual: KSP/KSPGetConvergedNegativeCurvature

source

PETSc.LibPETSc.KSPGetConvergedReason — Method

reason::KSPConvergedReason = KSPGetConvergedReason(petsclib::PetscLibType,ksp::PetscKSP)

Gets the reason the KSP iteration was stopped.

Not Collective

Input Parameter:

ksp - the KSP context

Output Parameter:

reason - negative value indicates diverged, positive value converged, see KSPConvergedReason for the possible values

Options Database Key:

-ksp_converged_reason - prints the reason to standard out when the solve ends

Level: intermediate

-seealso: , KSPConvergedReason, KSP, KSPSetConvergenceTest(), KSPConvergedDefault(), KSPSetTolerances(), KSPConvergedReasonView(), KSPGetConvergedReasonString()

External Links

PETSc Manual: KSP/KSPGetConvergedReason

source

PETSc.LibPETSc.KSPGetConvergedReasonString — Method

KSPGetConvergedReasonString(petsclib::PetscLibType,ksp::PetscKSP, strreason::String)

Return a human readable string for a KSPConvergedReason

Not Collective

Input Parameter:

ksp - the KSP context

Output Parameter:

strreason - a human readable string that describes ksp converged reason

Level: beginner

-seealso: , KSP, KSPGetConvergedReason()

External Links

PETSc Manual: KSP/KSPGetConvergedReasonString

source

PETSc.LibPETSc.KSPGetConvergenceContext — Method

KSPGetConvergenceContext(petsclib::PetscLibType,ksp::PetscKSP, ctx::Cvoid)

Gets the convergence context set with KSPSetConvergenceTest().

Not Collective

Input Parameter:

ksp - iterative solver obtained from KSPCreate()

Output Parameter:

ctx - monitoring context

Level: advanced

-seealso: , KSP, KSPConvergedDefault(), KSPSetConvergenceTest(), KSPGetConvergenceTest()

External Links

PETSc Manual: KSP/KSPGetConvergenceContext

source

PETSc.LibPETSc.KSPGetConvergenceTest — Method

KSPGetConvergenceTest(petsclib::PetscLibType,ksp::PetscKSP, converge::KSPConvergenceTestFn, ctx::Cvoid, destroy::PetscCtxDestroyFn)

Gets the function to be used to determine convergence.

Logically Collective

Input Parameter:

ksp - iterative solver obtained from KSPCreate()

Output Parameters:

converge - pointer to convergence test function, see KSPConvergenceTestFn
ctx - context for private data for the convergence routine (may be NULL)
destroy - a routine for destroying the context (may be NULL)

Level: advanced

-seealso: , KSP, KSPConvergedDefault(), KSPGetConvergenceContext(), KSPSetTolerances(), KSPSetConvergenceTest(), KSPGetAndClearConvergenceTest()

External Links

PETSc Manual: KSP/KSPGetConvergenceTest

source

PETSc.LibPETSc.KSPGetDM — Method

dm::PetscDM = KSPGetDM(petsclib::PetscLibType,ksp::PetscKSP)

Gets the DM that may be used by some preconditioners and that may be used to construct the linear system

Not Collective

Input Parameter:

ksp - the KSP

Output Parameter:

dm - the DM

Level: intermediate

-seealso: , KSP, DM, KSPSetDM(), KSPSetDMActive()

External Links

PETSc Manual: KSP/KSPGetDM

source

PETSc.LibPETSc.KSPGetDiagonalScale — Method

scale::PetscBool = KSPGetDiagonalScale(petsclib::PetscLibType,ksp::PetscKSP)

Checks if KSP solver scales the matrix and right

Not Collective

Input Parameter:

ksp - the KSP context

Output Parameter:

scale - PETSC_TRUE or PETSC_FALSE

Level: intermediate

-seealso: , KSP, KSPSetDiagonalScale(), KSPSetDiagonalScaleFix()

External Links

PETSc Manual: KSP/KSPGetDiagonalScale

source

PETSc.LibPETSc.KSPGetDiagonalScaleFix — Method

fix::PetscBool = KSPGetDiagonalScaleFix(petsclib::PetscLibType,ksp::PetscKSP)

Determines if KSP diagonally scales the system back after solving. That is KSPSetDiagonalScaleFix() has been called

Not Collective

Input Parameter:

ksp - the KSP context

Output Parameter:

fix - PETSC_TRUE to scale back after the system solve, PETSC_FALSE to not

rescale (default)

Level: intermediate

-seealso: , KSPGetDiagonalScale(), KSPSetDiagonalScale(), KSPSetDiagonalScaleFix(), KSP

External Links

PETSc Manual: KSP/KSPGetDiagonalScaleFix

source

PETSc.LibPETSc.KSPGetErrorHistory — Method

a::Vector{PetscReal},na::PetscInt = KSPGetErrorHistory(petsclib::PetscLibType,ksp::PetscKSP)

Gets the array used to hold the error history and the number of residuals it contains.

Not Collective

Input Parameter:

ksp - iterative solver obtained from KSPCreate()

Output Parameters:

a - pointer to array to hold history (or NULL)
na - number of used entries in a (or NULL)

Level: advanced

-seealso: , KSPSetErrorHistory(), KSPGetResidualHistory(), KSP

External Links

PETSc Manual: KSP/KSPGetErrorHistory

source

PETSc.LibPETSc.KSPGetErrorIfNotConverged — Method

flag::PetscBool = KSPGetErrorIfNotConverged(petsclib::PetscLibType,ksp::PetscKSP)

Will KSPSolve() generate an error if the solver does not converge?

Not Collective

Input Parameter:

ksp - iterative solver obtained from KSPCreate()

Output Parameter:

flag - PETSC_TRUE if it will generate an error, else PETSC_FALSE

Level: intermediate

-seealso: , KSPSetErrorIfNotConverged(), KSP

External Links

PETSc Manual: KSP/KSPGetErrorIfNotConverged

source

PETSc.LibPETSc.KSPGetGuess — Method

KSPGetGuess(petsclib::PetscLibType,ksp::PetscKSP, guess::KSPGuess)

Gets the initial guess generator for the KSP.

Not Collective

Input Parameter:

ksp - the Krylov context

Output Parameter:

guess - the object

Level: developer

-seealso: , KSPGuess, KSP, KSPSetOptionsPrefix(), KSPAppendOptionsPrefix(), KSPSetUseFischerGuess(), KSPSetGuess()

External Links

PETSc Manual: KSP/KSPGetGuess

source

PETSc.LibPETSc.KSPGetInitialGuessKnoll — Method

flag::PetscBool = KSPGetInitialGuessKnoll(petsclib::PetscLibType,ksp::PetscKSP)

Determines whether the KSP solver is using the Knoll trick (using PCApply(pc,b,...) to compute the initial guess

Not Collective

Input Parameter:

ksp - iterative solver obtained from KSPCreate()

Output Parameter:

flag - PETSC_TRUE if using Knoll trick, else PETSC_FALSE

Level: advanced

-seealso: , KSPSetInitialGuessKnoll(), KSPSetInitialGuessNonzero(), KSPGetInitialGuessNonzero(), KSP

External Links

PETSc Manual: KSP/KSPGetInitialGuessKnoll

source

PETSc.LibPETSc.KSPGetInitialGuessNonzero — Method

flag::PetscBool = KSPGetInitialGuessNonzero(petsclib::PetscLibType,ksp::PetscKSP)

Determines whether the KSP solver is using a zero initial guess.

Not Collective

Input Parameter:

ksp - iterative solver obtained from KSPCreate()

Output Parameter:

flag - PETSC_TRUE if guess is nonzero, else PETSC_FALSE

Level: intermediate

-seealso: , KSPSetInitialGuessNonzero(), KSP

External Links

PETSc Manual: KSP/KSPGetInitialGuessNonzero

source

PETSc.LibPETSc.KSPGetIterationNumber — Method

its::PetscInt = KSPGetIterationNumber(petsclib::PetscLibType,ksp::PetscKSP)

Gets the current iteration number; if the KSPSolve() is complete, returns the number of iterations used.

Not Collective

Input Parameter:

ksp - the iterative context

Output Parameter:

its - number of iterations

Level: intermediate

-seealso: , KSP, KSPGetResidualNorm(), KSPBuildResidual(), KSPGetTotalIterations()

External Links

PETSc Manual: KSP/KSPGetIterationNumber

source

PETSc.LibPETSc.KSPGetMatSolveBatchSize — Method

bs::PetscInt = KSPGetMatSolveBatchSize(petsclib::PetscLibType,ksp::PetscKSP)

Gets the maximum number of columns treated simultaneously in KSPMatSolve().

Input Parameter:

ksp - iterative solver context

Output Parameter:

bs - batch size

Level: advanced

-seealso: , KSPMatSolve(), KSPSetMatSolveBatchSize(), -mat_mumps_icntl_27, -matmatmult_Bbn

External Links

PETSc Manual: KSP/KSPGetMatSolveBatchSize

source

PETSc.LibPETSc.KSPGetMinimumIterations — Method

minit::PetscInt = KSPGetMinimumIterations(petsclib::PetscLibType,ksp::PetscKSP)

Gets the minimum number of iterations to use, regardless of the tolerances, that was set with KSPSetMinimumIterations() or `

Not Collective

Input Parameter:

ksp - the Krylov subspace context

Output Parameter:

minit - minimum number of iterations to use

Level: intermediate

-seealso: , KSPGetTolerances(), KSPConvergedDefault(), KSPSetConvergenceTest(), KSP, KSPSetTolerances(), KSPSetMinimumIterations()

External Links

PETSc Manual: KSP/KSPGetMinimumIterations

source

PETSc.LibPETSc.KSPGetMonitorContext — Method

KSPGetMonitorContext(petsclib::PetscLibType,ksp::PetscKSP, ctx::Cvoid)

Gets the monitoring context, as set by KSPMonitorSet() for the FIRST monitor only.

Not Collective

Input Parameter:

ksp - iterative solver obtained from KSPCreate()

Output Parameter:

ctx - monitoring context

Level: intermediate

-seealso: , KSPMonitorResidual(), KSP

External Links

PETSc Manual: KSP/KSPGetMonitorContext

source

PETSc.LibPETSc.KSPGetNestLevel — Method

level::PetscInt = KSPGetNestLevel(petsclib::PetscLibType,ksp::PetscKSP)

gets the amount of nesting the KSP has

Not Collective

Input Parameter:

ksp - the KSP

Output Parameter:

level - the nest level

Level: developer

-seealso: , KSPSetUp(), KSPSolve(), KSPDestroy(), KSP, KSPGMRES, KSPType, KSPSetNestLevel(), PCSetKSPNestLevel(), PCGetKSPNestLevel()

External Links

PETSc Manual: KSP/KSPGetNestLevel

source

PETSc.LibPETSc.KSPGetNormType — Method

normtype::KSPNormType = KSPGetNormType(petsclib::PetscLibType,ksp::PetscKSP)

Gets the KSPNormType that is used for convergence testing during KSPSolve() for this KSP context

Not Collective

Input Parameter:

ksp - Krylov solver context

Output Parameter:

normtype - the KSPNormType that is used for convergence testing

Level: advanced

-seealso: , KSPNormType, KSPSetNormType(), KSPConvergedSkip()

External Links

PETSc Manual: KSP/KSPGetNormType

source

PETSc.LibPETSc.KSPGetOperators — Method

Amat, PMat = KSPGetOperators(petsclib::PetscLibType,ksp::PetscKSP)

Gets the matrix associated with the linear system and a (possibly) different one used to construct the preconditioner from the KSP context

Collective

Input Parameter:

ksp - the KSP context

Output Parameters:

Amat - the matrix that defines the linear system
Pmat - the matrix to be used in constructing the preconditioner, usually the same as Amat.

Level: intermediate

-seealso: , KSP, KSPSolve(), KSPGetPC(), PCSetOperators(), KSPSetOperators(), KSPGetOperatorsSet()

External Links

PETSc Manual: KSP/KSPGetOperators

source

PETSc.LibPETSc.KSPGetOperatorsSet — Method

mat::PetscBool,pmat::PetscBool = KSPGetOperatorsSet(petsclib::PetscLibType,ksp::PetscKSP)

Determines if the matrix associated with the linear system and possibly a different one from which the preconditioner will be built have been set in the KSP with KSPSetOperators()

Not Collective, though the results on all processes will be the same

Input Parameter:

ksp - the KSP context

Output Parameters:

mat - the matrix associated with the linear system was set
pmat - matrix from which the preconditioner will be built, usually the same as mat was set

Level: intermediate

-seealso: , KSP, PCSetOperators(), KSPGetOperators(), KSPSetOperators(), PCGetOperators(), PCGetOperatorsSet()

External Links

PETSc Manual: KSP/KSPGetOperatorsSet

source

PETSc.LibPETSc.KSPGetOptionsPrefix — Method

prefix::String = KSPGetOptionsPrefix(petsclib::PetscLibType,ksp::PetscKSP)

Gets the prefix used for searching for all KSP options in the database.

Not Collective

Input Parameter:

ksp - the Krylov context

Output Parameter:

prefix - pointer to the prefix string used is returned

Level: advanced

-seealso: , KSP, KSPSetFromOptions(), KSPSetOptionsPrefix(), KSPAppendOptionsPrefix()

External Links

PETSc Manual: KSP/KSPGetOptionsPrefix

source

PETSc.LibPETSc.KSPGetPC — Method

KSPGetPC(petsclib::PetscLibType,ksp::PetscKSP, pc::PC)

Returns a pointer to the preconditioner context with the KSP

Not Collective

Input Parameter:

ksp - iterative solver obtained from KSPCreate()

Output Parameter:

pc - preconditioner context

Level: beginner

-seealso: , KSPSetPC(), KSP, PC

External Links

PETSc Manual: KSP/KSPGetPC

source

PETSc.LibPETSc.KSPGetPCSide — Method

KSPGetPCSide(petsclib::PetscLibType,ksp::PetscKSP, side::PCSide)

Gets the preconditioning side.

Not Collective

Input Parameter:

ksp - iterative solver obtained from KSPCreate()

Output Parameter:

side - the preconditioning side, where side is one of

-seealso: , KSPSetPCSide(), KSP

External Links

PETSc Manual: KSP/KSPGetPCSide

source

PETSc.LibPETSc.KSPGetResidualHistory — Method

a::Vector{PetscReal},na::PetscInt = KSPGetResidualHistory(petsclib::PetscLibType,ksp::PetscKSP)

Gets the array used to hold the residual history and the number of residuals it contains.

Not Collective

Input Parameter:

ksp - iterative solver obtained from KSPCreate()

Output Parameters:

a - pointer to array to hold history (or NULL)
na - number of used entries in a (or NULL). Note this has different meanings depending on the reset argument to KSPSetResidualHistory()

Level: advanced

-seealso: , KSPSetResidualHistory(), KSP, KSPGetIterationNumber(), KSPSTCG, KSPBCGSL

External Links

PETSc Manual: KSP/KSPGetResidualHistory

source

PETSc.LibPETSc.KSPGetResidualNorm — Method

rnorm::PetscReal = KSPGetResidualNorm(petsclib::PetscLibType,ksp::PetscKSP)

Gets the last (possibly approximate and/or preconditioned) residual norm that has been computed.

Not Collective

Input Parameter:

ksp - the iterative context

Output Parameter:

rnorm - residual norm

Level: intermediate

-seealso: , KSP, KSPSetNormType(), KSPBuildResidual(), KSPNormType

External Links

PETSc Manual: KSP/KSPGetResidualNorm

source

PETSc.LibPETSc.KSPGetReusePreconditioner — Method

flag::PetscBool = KSPGetReusePreconditioner(petsclib::PetscLibType,ksp::PetscKSP)

Determines if the KSP reuses the current preconditioner even if the Mat operator in the KSP has changed.

Collective

Input Parameter:

ksp - iterative solver obtained from KSPCreate()

Output Parameter:

flag - the boolean flag indicating if the current preconditioner should be reused

Level: intermediate

-seealso: , KSPCreate(), KSPSolve(), KSPDestroy(), KSPSetReusePreconditioner(), KSP

External Links

PETSc Manual: KSP/KSPGetReusePreconditioner

source

PETSc.LibPETSc.KSPGetRhs — Method

r::PetscVec = KSPGetRhs(petsclib::PetscLibType,ksp::PetscKSP)

Gets the right be solved.

Not Collective

Input Parameter:

ksp - iterative solver obtained from KSPCreate()

Output Parameter:

r - right-hand-side vector

Level: developer

-seealso: , KSPGetSolution(), KSPSolve(), KSP

External Links

PETSc Manual: KSP/KSPGetRhs

source

PETSc.LibPETSc.KSPGetSolution — Method

v::PetscVec = KSPGetSolution(petsclib::PetscLibType,ksp::PetscKSP)

Gets the location of the solution for the linear system to be solved.

Not Collective

Input Parameter:

ksp - iterative solver obtained from KSPCreate()

Return Value:

v - solution vector

Level: developer

-seealso: , KSPGetRhs(), KSPBuildSolution(), KSPSolve(), KSP

External Links

PETSc Manual: KSP/KSPGetSolution

source

PETSc.LibPETSc.KSPGetTolerances — Method

rtol::PetscReal,abstol::PetscReal,dtol::PetscReal,maxits::PetscInt = KSPGetTolerances(petsclib::PetscLibType,ksp::PetscKSP)

Gets the relative, absolute, divergence, and maximum iteration tolerances used by the default KSP convergence tests.

Not Collective

Input Parameter:

ksp - the Krylov subspace context

Output Parameters:

rtol - the relative convergence tolerance
abstol - the absolute convergence tolerance
dtol - the divergence tolerance
maxits - maximum number of iterations

Level: intermediate

-seealso: , KSPSetTolerances(), KSP, KSPSetMinimumIterations(), KSPGetMinimumIterations()

External Links

PETSc Manual: KSP/KSPGetTolerances

source

PETSc.LibPETSc.KSPGetTotalIterations — Method

its::PetscInt = KSPGetTotalIterations(petsclib::PetscLibType,ksp::PetscKSP)

Gets the total number of iterations this KSP object has performed since was created, counted over all linear solves

Not Collective

Input Parameter:

ksp - the iterative context

Output Parameter:

its - total number of iterations

Level: intermediate

-seealso: , KSP, KSPBuildResidual(), KSPGetResidualNorm(), KSPGetIterationNumber()

External Links

PETSc Manual: KSP/KSPGetTotalIterations

source

PETSc.LibPETSc.KSPGetType — Method

type::KSPType = KSPGetType(petsclib::PetscLibType,ksp::PetscKSP)

Gets the KSP type as a string from the KSP object.

Not Collective

Input Parameter:

ksp - Krylov context

Output Parameter:

type - name of the KSP method

Level: intermediate

-seealso: , KSPType, KSP, KSPSetType()

External Links

PETSc Manual: KSP/KSPGetType

source

PETSc.LibPETSc.KSPHPDDMGetDeflationMat — Method

KSPHPDDMGetDeflationMat(petsclib::PetscLibType,ksp::PetscKSP, U::PetscMat)

External Links

PETSc Manual: KSP/KSPHPDDMGetDeflationMat

source

PETSc.LibPETSc.KSPHPDDMGetType — Method

type::KSPHPDDMType = KSPHPDDMGetType(petsclib::PetscLibType,ksp::PetscKSP)

External Links

PETSc Manual: KSP/KSPHPDDMGetType

source

PETSc.LibPETSc.KSPHPDDMSetDeflationMat — Method

KSPHPDDMSetDeflationMat(petsclib::PetscLibType,ksp::PetscKSP, U::PetscMat)

External Links

PETSc Manual: KSP/KSPHPDDMSetDeflationMat

source

PETSc.LibPETSc.KSPHPDDMSetType — Method

KSPHPDDMSetType(petsclib::PetscLibType,ksp::PetscKSP, type::KSPHPDDMType)

External Links

PETSc Manual: KSP/KSPHPDDMSetType

source

PETSc.LibPETSc.KSPInitialResidual — Method

KSPInitialResidual(petsclib::PetscLibType,ksp::PetscKSP, vsoln::PetscVec, vt1::PetscVec, vt2::PetscVec, vres::PetscVec, vb::PetscVec)

Computes the residual. Either b preconditioning or C(b - Ax) with left preconditioning; the latter residual is often called the "preconditioned residual".

Collective

Input Parameters:

ksp - the KSP solver object
vsoln - solution to use in computing residual
vt1 - temporary work vector
vt2 - temporary work vector
vb - right-hand-side vector

Output Parameter:

vres - calculated residual

Level: developer

-seealso: , KSP, KSPSolve(), KSPMonitor()

External Links

PETSc Manual: KSP/KSPInitialResidual

source

PETSc.LibPETSc.KSPInitializePackage — Method

KSPInitializePackage(petsclib::PetscLibType)

This function initializes everything in the KSP package. It is called from PetscDLLibraryRegister_petscksp() when using dynamic libraries, and on the first call to KSPCreate() when using shared or static libraries.

Level: developer

-seealso: , PetscInitialize(), KSPFinalizePackage()

External Links

PETSc Manual: KSP/KSPInitializePackage

source

PETSc.LibPETSc.KSPLGMRESSetAugDim — Method

KSPLGMRESSetAugDim(petsclib::PetscLibType,ksp::PetscKSP, dim::PetscInt)

Set the number of error approximations to include in the approximation space (default is 2) for KSPLGMRES

Collective

Input Parameters:

ksp - the KSP context
dim - the number of vectors to use

Options Database Key:

-ksp_lgmres_augment dim - the number of error approximations to include

Level: intermediate

-seealso: , KSPLGMRES, KSPLGMRESSetConstant()

External Links

PETSc Manual: KSP/KSPLGMRESSetAugDim

source

PETSc.LibPETSc.KSPLGMRESSetConstant — Method

KSPLGMRESSetConstant(petsclib::PetscLibType,ksp::PetscKSP)

keep the error approximation space a constant size for every restart cycle

Collective

Input Parameters:

ksp - the KSP context

Options Database Key:

-ksp_lgmres_constant - set the size to be constant

Level: intermediate

-seealso: , KSPLGMRES, KSPLGMRESSetAugDim()

External Links

PETSc Manual: KSP/KSPLGMRESSetConstant

source

PETSc.LibPETSc.KSPLSQRConvergedDefault — Method

KSPLSQRConvergedDefault(petsclib::PetscLibType,ksp::PetscKSP, n::PetscInt, rnorm::PetscReal, reason::KSPConvergedReason, ctx::Cvoid)

Determines convergence of the KSPLSQR Krylov method, including a check on the residual norm of the normal equations.

Collective

Input Parameters:

ksp - iterative context
n - iteration number
rnorm - 2-norm residual value (may be estimated)
ctx - convergence context which must have been created by KSPConvergedDefaultCreate()

Output Parameter:

reason - the convergence reason

Level: advanced

-seealso: , KSPLSQR, KSPSetConvergenceTest(), KSPSetTolerances(), KSPConvergedSkip(), KSPConvergedReason, KSPGetConvergedReason(), KSPConvergedDefaultSetUIRNorm(), KSPConvergedDefaultSetUMIRNorm(), KSPConvergedDefaultCreate(), KSPConvergedDefaultDestroy(), KSPConvergedDefault(), KSPLSQRGetNorms(), KSPLSQRSetExactMatNorm()

External Links

PETSc Manual: KSP/KSPLSQRConvergedDefault

source

PETSc.LibPETSc.KSPLSQRGetNorms — Method

arnorm::PetscReal,anorm::PetscReal = KSPLSQRGetNorms(petsclib::PetscLibType,ksp::PetscKSP)

Get the norm estimates that KSPLSQR computes internally during KSPSolve().

Not Collective

Input Parameter:

ksp - iterative context

Output Parameters:

arnorm - good estimate of (APmat^{-T})r, where r = A x - b, used in specific stopping criterion
anorm - poor estimate of A*Pmat^{-T}_{frobenius} used in specific stopping criterion

Level: intermediate

-seealso: , KSPSolve(), KSPLSQR, KSPLSQRSetExactMatNorm()

External Links

PETSc Manual: KSP/KSPLSQRGetNorms

source

PETSc.LibPETSc.KSPLSQRGetStandardErrorVec — Method

KSPLSQRGetStandardErrorVec(petsclib::PetscLibType,ksp::PetscKSP, se::PetscVec)

Get vector of standard error estimates. Only available if -ksplsqrsetstandarderror was set to true or KSPLSQRSetComputeStandardErrorVec(ksp, PETSC_TRUE) was called. Otherwise returns NULL.

Not Collective

Input Parameter:

ksp - iterative context

Output Parameter:

se - vector of standard estimates

Level: intermediate

-seealso: , KSPSolve(), KSPLSQR, KSPLSQRSetComputeStandardErrorVec()

External Links

PETSc Manual: KSP/KSPLSQRGetStandardErrorVec

source

PETSc.LibPETSc.KSPLSQRMonitorResidual — Method

KSPLSQRMonitorResidual(petsclib::PetscLibType,ksp::PetscKSP, n::PetscInt, rnorm::PetscReal, vf::PetscViewerAndFormat)

Prints the residual norm, as well as the normal equation residual norm, at each iteration of an iterative solver for the KSPLSQR solver

Collective

Input Parameters:

ksp - iterative context
n - iteration number
rnorm - 2-norm (preconditioned) residual value (may be estimated).
vf - The viewer context

Options Database Key:

-ksp_lsqr_monitor - Activates KSPLSQRMonitorResidual()

Level: intermediate

-seealso: , KSPLSQR, KSPMonitorSet(), KSPMonitorResidual(), KSPMonitorTrueResidualMaxNorm(), KSPLSQRMonitorResidualDrawLG()

External Links

PETSc Manual: KSP/KSPLSQRMonitorResidual

source

PETSc.LibPETSc.KSPLSQRMonitorResidualDrawLG — Method

KSPLSQRMonitorResidualDrawLG(petsclib::PetscLibType,ksp::PetscKSP, n::PetscInt, rnorm::PetscReal, vf::PetscViewerAndFormat)

Plots the true residual norm at each iteration of an iterative solver for the KSPLSQR solver

Collective

Input Parameters:

ksp - iterative context
n - iteration number
rnorm - 2-norm (preconditioned) residual value (may be estimated).
vf - The viewer context

Options Database Key:

-ksp_lsqr_monitor draw::draw_lg - Activates KSPMonitorTrueResidualDrawLG()

Level: intermediate

-seealso: , KSPLSQR, KSPMonitorSet(), KSPMonitorTrueResidual(), KSPLSQRMonitorResidual(), KSPLSQRMonitorResidualDrawLGCreate()

External Links

PETSc Manual: KSP/KSPLSQRMonitorResidualDrawLG

source

PETSc.LibPETSc.KSPLSQRMonitorResidualDrawLGCreate — Method

vf::PetscViewerAndFormat = KSPLSQRMonitorResidualDrawLGCreate(petsclib::PetscLibType,viewer::PetscViewer, format::PetscViewerFormat, ctx::Cvoid)

Creates the line graph object for the KSPLSQR residual and normal equation residual norm

Collective

Input Parameters:

viewer - The PetscViewer
format - The viewer format
ctx - An optional user context

Output Parameter:

vf - The PetscViewerAndFormat

Level: intermediate

-seealso: , KSPLSQR, KSPMonitorSet(), KSPLSQRMonitorResidual(), KSPLSQRMonitorResidualDrawLG()

External Links

PETSc Manual: KSP/KSPLSQRMonitorResidualDrawLGCreate

source

PETSc.LibPETSc.KSPLSQRSetComputeStandardErrorVec — Method

KSPLSQRSetComputeStandardErrorVec(petsclib::PetscLibType,ksp::PetscKSP, flg::PetscBool)

Compute a vector of standard error estimates during KSPSolve() for KSPLSQR.

Logically Collective

Input Parameters:

ksp - iterative context
flg - compute the vector of standard estimates or not

Level: intermediate

-seealso: , KSPSolve(), KSPLSQR, KSPLSQRGetStandardErrorVec()

External Links

PETSc Manual: KSP/KSPLSQRSetComputeStandardErrorVec

source

PETSc.LibPETSc.KSPLSQRSetExactMatNorm — Method

KSPLSQRSetExactMatNorm(petsclib::PetscLibType,ksp::PetscKSP, flg::PetscBool)

Compute exact matrix norm instead of iteratively refined estimate.

Not Collective

Input Parameters:

ksp - iterative context
flg - compute exact matrix norm or not

Level: intermediate

-seealso: , KSPSolve(), KSPLSQR, KSPLSQRGetNorms(), KSPLSQRConvergedDefault()

External Links

PETSc Manual: KSP/KSPLSQRSetExactMatNorm

source

PETSc.LibPETSc.KSPLoad — Method

KSPLoad(petsclib::PetscLibType,newdm::PetscKSP, viewer::PetscViewer)

Loads a KSP that has been stored in a PETSCVIEWERBINARY with KSPView().

Collective

Input Parameters:

newdm - the newly loaded KSP, this needs to have been created with KSPCreate() or

some related function before a call to KSPLoad().

viewer - binary file viewer, obtained from PetscViewerBinaryOpen()

Level: intermediate

-seealso: , KSP, PetscViewerBinaryOpen(), KSPView(), MatLoad(), VecLoad()

External Links

PETSc Manual: KSP/KSPLoad

source

PETSc.LibPETSc.KSPMINRESGetUseQLP — Method

qlp::PetscBool = KSPMINRESGetUseQLP(petsclib::PetscLibType,ksp::PetscKSP)

Get the flag that indicates if the QLP variant is being used

Logically Collective

Input Parameter:

ksp - the iterative context

Output Parameter:

qlp - a Boolean indicating if the QLP variant is used

Level: beginner

-seealso: , KSP, KSPMINRES, KSPMINRESSetUseQLP()

External Links

PETSc Manual: KSP/KSPMINRESGetUseQLP

source

PETSc.LibPETSc.KSPMINRESSetRadius — Method

KSPMINRESSetRadius(petsclib::PetscLibType,ksp::PetscKSP, radius::PetscReal)

Set the maximum solution norm allowed for use with trust region methods

Logically Collective

Input Parameters:

ksp - the iterative context
radius - the value

Level: beginner

Options Database Key:

-ksp_minres_radius <real> - maximum allowed solution norm

-seealso: , KSP, KSPMINRES, KSPMINRESSetUseQLP()

External Links

PETSc Manual: KSP/KSPMINRESSetRadius

source

PETSc.LibPETSc.KSPMINRESSetUseQLP — Method

KSPMINRESSetUseQLP(petsclib::PetscLibType,ksp::PetscKSP, qlp::PetscBool)

Use the QLP variant of KSPMINRES

Logically Collective

Input Parameters:

ksp - the iterative context
qlp - a Boolean indicating if the QLP variant should be used

Level: beginner

-seealso: , KSP, KSPMINRES, KSPMINRESGetUseQLP()

External Links

PETSc Manual: KSP/KSPMINRESSetUseQLP

source

PETSc.LibPETSc.KSPMatSolve — Method

KSPMatSolve(petsclib::PetscLibType,ksp::PetscKSP, B::PetscMat, X::PetscMat)

Solves a linear system with multiple right

Input Parameters:

ksp - iterative solver
B - block of right-hand sides

Output Parameter:

X - block of solutions

Level: intermediate

-seealso: , KSPSolve(), MatMatSolve(), KSPMatSolveTranspose(), MATDENSE, KSPHPDDM, PCBJACOBI, PCASM, KSPSetMatSolveBatchSize()

External Links

PETSc Manual: KSP/KSPMatSolve

source

PETSc.LibPETSc.KSPMatSolveTranspose — Method

KSPMatSolveTranspose(petsclib::PetscLibType,ksp::PetscKSP, B::PetscMat, X::PetscMat)

Solves a linear system with the transposed matrix with multiple right

Input Parameters:

ksp - iterative solver
B - block of right-hand sides

Output Parameter:

X - block of solutions

Level: intermediate

-seealso: , KSPSolveTranspose(), MatMatTransposeSolve(), KSPMatSolve(), MATDENSE, KSPHPDDM, PCBJACOBI, PCASM

External Links

PETSc Manual: KSP/KSPMatSolveTranspose

source

PETSc.LibPETSc.KSPMonitor — Method

KSPMonitor(petsclib::PetscLibType,ksp::PetscKSP, it::PetscInt, rnorm::PetscReal)

runs the user provided monitor routines, if they exist

Collective

Input Parameters:

ksp - iterative solver obtained from KSPCreate()
it - iteration number
rnorm - relative norm of the residual

Level: developer

-seealso: , KSPMonitorSet()

External Links

PETSc Manual: KSP/KSPMonitor

source

PETSc.LibPETSc.KSPMonitorCancel — Method

KSPMonitorCancel(petsclib::PetscLibType,ksp::PetscKSP)

Clears all monitors for a KSP object.

Logically Collective

Input Parameter:

ksp - iterative solver obtained from KSPCreate()

Options Database Key:

-ksp_monitor_cancel - Cancels all monitors that have been hardwired into a code by calls to KSPMonitorSet(), but does not cancel those set via the options database.

Level: intermediate

-seealso: , KSPMonitorResidual(), KSPMonitorSet(), KSP

External Links

PETSc Manual: KSP/KSPMonitorCancel

source

PETSc.LibPETSc.KSPMonitorDynamicTolerance — Method

KSPMonitorDynamicTolerance(petsclib::PetscLibType,ksp::PetscKSP, its::PetscInt, fnorm::PetscReal, ctx::Cvoid)

A monitor that changes the inner tolerance of nested preconditioners in every outer iteration in an adaptive way.

Collective

Input Parameters:

ksp - iterative context
its - iteration number (not used)
fnorm - the current residual norm
ctx - context used by monitor

Options Database Key:

-sub_ksp_dynamic_tolerance <coef> - coefficient of dynamic tolerance for inner solver, default is 1.0

Level: advanced

-seealso: , KSP, KSPMonitorDynamicToleranceCreate(), KSPMonitorDynamicToleranceDestroy(), KSPMonitorDynamicToleranceSetCoefficient()

External Links

PETSc Manual: KSP/KSPMonitorDynamicTolerance

source

PETSc.LibPETSc.KSPMonitorDynamicToleranceCreate — Method

ctx::Cvoid = KSPMonitorDynamicToleranceCreate(petsclib::PetscLibType)

Creates the context used by KSPMonitorDynamicTolerance()

Logically Collective

Output Parameter:

ctx - a void pointer

Options Database Key:

-sub_ksp_dynamic_tolerance <coef> - coefficient of dynamic tolerance for inner solver, default is 1.0

Level: advanced

-seealso: , KSP, KSPMonitorDynamicTolerance(), KSPMonitorDynamicToleranceDestroy(), KSPMonitorDynamicToleranceSetCoefficient()

External Links

PETSc Manual: KSP/KSPMonitorDynamicToleranceCreate

source

PETSc.LibPETSc.KSPMonitorDynamicToleranceDestroy — Method

KSPMonitorDynamicToleranceDestroy(petsclib::PetscLibType,ctx::Cvoid)

Destroy the monitor context used in KSPMonitorDynamicTolerance()

Input Parameter:

ctx - the monitor context

Level: advanced

-seealso: , KSP, KSPMonitorDynamicTolerance(), KSPMonitorSet(), KSPMonitorDynamicToleranceCreate()

External Links

PETSc Manual: KSP/KSPMonitorDynamicToleranceDestroy

source

PETSc.LibPETSc.KSPMonitorDynamicToleranceSetCoefficient — Method

coeff::PetscReal = KSPMonitorDynamicToleranceSetCoefficient(petsclib::PetscLibType,ctx::Cvoid)

Sets the coefficient in the context used by KSPMonitorDynamicTolerance()

Logically Collective

Output Parameters:

ctx - the context for KSPMonitorDynamicTolerance()
coeff - the coefficient, default is 1.0

Options Database Key:

-sub_ksp_dynamic_tolerance <coef> - coefficient of dynamic tolerance for inner solver, default is 1.0

Level: advanced

-seealso: , KSP, KSPMonitorDynamicTolerance(), KSPMonitorDynamicToleranceDestroy(), KSPMonitorDynamicToleranceCreate()

External Links

PETSc Manual: KSP/KSPMonitorDynamicToleranceSetCoefficient

source

PETSc.LibPETSc.KSPMonitorError — Method

KSPMonitorError(petsclib::PetscLibType,ksp::PetscKSP, n::PetscInt, rnorm::PetscReal, vf::PetscViewerAndFormat)

Prints the error norm, as well as the (possibly preconditioned) residual norm, at each iteration of an iterative solver.

Collective

Input Parameters:

ksp - iterative context
n - iteration number
rnorm - 2-norm (preconditioned) residual value (may be estimated).
vf - The viewer context

Options Database Key:

-ksp_monitor_error - Activates KSPMonitorError()

Level: intermediate

-seealso: , KSP, KSPMonitorSet(), KSPMonitorResidual(), KSPMonitorTrueResidualMaxNorm()

External Links

PETSc Manual: KSP/KSPMonitorError

source

PETSc.LibPETSc.KSPMonitorErrorDraw — Method

KSPMonitorErrorDraw(petsclib::PetscLibType,ksp::PetscKSP, n::PetscInt, rnorm::PetscReal, vf::PetscViewerAndFormat)

Plots the error at each iteration of an iterative solver.

Collective

Input Parameters:

ksp - iterative context
n - iteration number
rnorm - 2-norm (preconditioned) residual value (may be estimated).
vf - The viewer context

Options Database Key:

-ksp_monitor_error draw - Activates KSPMonitorErrorDraw()

Level: intermediate

-seealso: , PETSCVIEWERDRAW, KSP, KSPMonitorSet(), KSPMonitorTrueResidual(), KSPMonitorErrorDrawLG()

External Links

PETSc Manual: KSP/KSPMonitorErrorDraw

source

PETSc.LibPETSc.KSPMonitorErrorDrawLG — Method

KSPMonitorErrorDrawLG(petsclib::PetscLibType,ksp::PetscKSP, n::PetscInt, rnorm::PetscReal, vf::PetscViewerAndFormat)

Plots the error and residual norm at each iteration of an iterative solver.

Collective

Input Parameters:

ksp - iterative context
n - iteration number
rnorm - 2-norm (preconditioned) residual value (may be estimated).
vf - The viewer context

Options Database Key:

-ksp_monitor_error draw::draw_lg - Activates KSPMonitorTrueResidualDrawLG()

Level: intermediate

-seealso: , PETSCVIEWERDRAW, KSP, KSPMonitorSet(), KSPMonitorTrueResidual(), KSPMonitorErrorDraw()

External Links

PETSc Manual: KSP/KSPMonitorErrorDrawLG

source

PETSc.LibPETSc.KSPMonitorErrorDrawLGCreate — Method

vf::PetscViewerAndFormat = KSPMonitorErrorDrawLGCreate(petsclib::PetscLibType,viewer::PetscViewer, format::PetscViewerFormat, ctx::Cvoid)

Creates the context for the error and preconditioned residual plotter KSPMonitorErrorDrawLG()

Collective

Input Parameters:

viewer - The PetscViewer
format - The viewer format
ctx - An optional user context

Output Parameter:

vf - The viewer context

Level: intermediate

-seealso: , PETSCVIEWERDRAW, KSP, KSPMonitorSet(), KSPMonitorTrueResidual(), KSPMonitorErrorDrawLG()

External Links

PETSc Manual: KSP/KSPMonitorErrorDrawLGCreate

source

PETSc.LibPETSc.KSPMonitorLGRange — Method

KSPMonitorLGRange(petsclib::PetscLibType,ksp::PetscKSP, n::PetscInt, rnorm::PetscReal, monctx::Cvoid)

External Links

PETSc Manual: KSP/KSPMonitorLGRange

source

PETSc.LibPETSc.KSPMonitorRegister — Method

KSPMonitorRegister(petsclib::PetscLibType,name::String, vtype::PetscViewerType, format::PetscViewerFormat, monitor::KSPMonitorRegisterFn, create::KSPMonitorRegisterCreateFn, destroy::KSPMonitorRegisterDestroyFn)

Registers a Krylov subspace solver monitor routine that may be accessed with KSPMonitorSetFromOptions()

Not Collective

Input Parameters:

name - name of a new monitor type
vtype - A PetscViewerType for the output
format - A PetscViewerFormat for the output
monitor - Monitor routine, see KSPMonitorRegisterFn
create - Creation routine, or NULL
destroy - Destruction routine, or NULL

Level: advanced

-seealso: , KSP, KSPMonitorSet(), KSPMonitorRegisterAll(), KSPMonitorSetFromOptions()

External Links

PETSc Manual: KSP/KSPMonitorRegister

source

PETSc.LibPETSc.KSPMonitorResidual — Method

KSPMonitorResidual(petsclib::PetscLibType,ksp::PetscKSP, n::PetscInt, rnorm::PetscReal, vf::PetscViewerAndFormat)

Print the (possibly preconditioned, possibly approximate) residual norm at each iteration of an iterative solver.

Collective

Input Parameters:

ksp - iterative context
n - iteration number
rnorm - (preconditioned) residual norm value (may be estimated).
vf - The viewer context

Options Database Key:

-ksp_monitor - Activates KSPMonitorResidual() to print the norm value at each iteration

Level: intermediate

-seealso: , KSP, KSPMonitorSet(), KSPMonitorTrueResidual(), KSPMonitorResidualView(), KSPMonitorResidualDrawLG(), KSPMonitorResidualRange(), KSPMonitorTrueResidualDraw(), KSPMonitorTrueResidualDrawLG(), KSPMonitorTrueResidualMax(), KSPMonitorSingularValue(), KSPMonitorSolutionDrawLG(), KSPMonitorSolutionDraw(), KSPMonitorSolution(), KSPMonitorErrorDrawLG(), KSPMonitorErrorDraw(), KSPMonitorError()

External Links

PETSc Manual: KSP/KSPMonitorResidual

source

PETSc.LibPETSc.KSPMonitorResidualDrawLG — Method

KSPMonitorResidualDrawLG(petsclib::PetscLibType,ksp::PetscKSP, n::PetscInt, rnorm::PetscReal, vf::PetscViewerAndFormat)

Plots the (possibly preconditioned) residual norm at each iteration of an iterative solver.

Collective

Input Parameters:

ksp - iterative context
n - iteration number
rnorm - 2-norm (preconditioned) residual value (may be estimated).
vf - The viewer context

Options Database Key:

-ksp_monitor draw::draw_lg - Activates KSPMonitorResidualDrawLG()

Level: intermediate

-seealso: , KSP, PETSCVIEWERDRAW, KSPMonitorSet(), KSPMonitorTrueResidual(), KSPMonitorResidualView(), KSPMonitorResidual()

External Links

PETSc Manual: KSP/KSPMonitorResidualDrawLG

source

PETSc.LibPETSc.KSPMonitorResidualDrawLGCreate — Method

vf::PetscViewerAndFormat = KSPMonitorResidualDrawLGCreate(petsclib::PetscLibType,viewer::PetscViewer, format::PetscViewerFormat, ctx::Cvoid)

Creates the context for the (possibly preconditioned) residual norm monitor KSPMonitorResidualDrawLG()

Collective

Input Parameters:

viewer - The PetscViewer of type PETSCVIEWERDRAW
format - The viewer format
ctx - An optional user context

Output Parameter:

vf - The viewer context

Level: intermediate

-seealso: , KSP, PETSCVIEWERDRAW, KSPMonitorSet(), KSPMonitorTrueResidual(), KSPMonitorResidualDrawLG(), PetscViewerFormat, PetscViewer, PetscViewerAndFormat

External Links

PETSc Manual: KSP/KSPMonitorResidualDrawLGCreate

source

PETSc.LibPETSc.KSPMonitorResidualRange — Method

KSPMonitorResidualRange(petsclib::PetscLibType,ksp::PetscKSP, it::PetscInt, rnorm::PetscReal, vf::PetscViewerAndFormat)

Prints the percentage of residual elements that are more than 10 percent of the maximum value.

Collective

Input Parameters:

ksp - iterative context
it - iteration number
rnorm - 2-norm (preconditioned) residual value (may be estimated).
vf - The viewer context

Options Database Key:

-ksp_monitor_range - Activates KSPMonitorResidualRange()

Level: intermediate

-seealso: , KSP, KSPMonitorSet(), KSPMonitorResidual()

External Links

PETSc Manual: KSP/KSPMonitorResidualRange

source

PETSc.LibPETSc.KSPMonitorResidualShort — Method

KSPMonitorResidualShort(petsclib::PetscLibType,ksp::PetscKSP, its::PetscInt, fnorm::PetscReal, vf::PetscViewerAndFormat)

External Links

PETSc Manual: KSP/KSPMonitorResidualShort

source

PETSc.LibPETSc.KSPMonitorResidualView — Method

KSPMonitorResidualView(petsclib::PetscLibType,ksp::PetscKSP, n::PetscInt, rnorm::PetscReal, vf::PetscViewerAndFormat)

Plots the (possibly preconditioned) residual at each iteration of an iterative solver.

Collective

Input Parameters:

ksp - iterative context
n - iteration number
rnorm - 2-norm (preconditioned) residual value (may be estimated).
vf - The viewer context

Options Database Key:

-ksp_monitor viewertype - Activates KSPMonitorResidualView()

Level: intermediate

-seealso: , KSP, KSPMonitorSet(), KSPMonitorTrueResidual(), KSPMonitorResidual(), KSPMonitorResidualDrawLG()

External Links

PETSc Manual: KSP/KSPMonitorResidualView

source

PETSc.LibPETSc.KSPMonitorSAWs — Method

KSPMonitorSAWs(petsclib::PetscLibType,ksp::PetscKSP, n::PetscInt, rnorm::PetscReal, ctx::Cvoid)

monitor KSP solution using SAWs

Logically Collective

Input Parameters:

ksp - iterative context
n - iteration number
rnorm - 2-norm (preconditioned) residual value (may be estimated).
ctx - created with KSPMonitorSAWsCreate()

Level: advanced

-seealso: , KSP, KSPMonitorSet(), KSPMonitorSAWsCreate(), KSPMonitorSAWsDestroy(), KSPMonitorSingularValue(), KSPComputeExtremeSingularValues(), PetscViewerSAWsOpen()

External Links

PETSc Manual: KSP/KSPMonitorSAWs

source

PETSc.LibPETSc.KSPMonitorSAWsCreate — Method

ctx::Cvoid = KSPMonitorSAWsCreate(petsclib::PetscLibType,ksp::PetscKSP)

create an SAWs monitor context for KSP

Collective

Input Parameter:

ksp - KSP to monitor

Output Parameter:

ctx - context for monitor

Level: developer

-seealso: , KSP, KSPMonitorSet(), KSPMonitorSAWs(), KSPMonitorSAWsDestroy()

External Links

PETSc Manual: KSP/KSPMonitorSAWsCreate

source

PETSc.LibPETSc.KSPMonitorSAWsDestroy — Method

KSPMonitorSAWsDestroy(petsclib::PetscLibType,ctx::Cvoid)

destroy a monitor context created with KSPMonitorSAWsCreate()

Collective

Input Parameter:

ctx - monitor context

Level: developer

-seealso: , KSP, KSPMonitorSet(), KSPMonitorSAWsCreate()

External Links

PETSc Manual: KSP/KSPMonitorSAWsDestroy

source

PETSc.LibPETSc.KSPMonitorSNESResidual — Method

KSPMonitorSNESResidual(petsclib::PetscLibType,ksp::PetscKSP, n::PetscInt, rnorm::PetscReal, vf::PetscViewerAndFormat)

Prints the SNES residual norm, as well as the KSP residual norm, at each iteration of a KSPSolve() called within a SNESSolve().

Collective

Input Parameters:

ksp - iterative context
n - iteration number
rnorm - 2-norm (preconditioned) residual value (may be estimated).
vf - The viewer context

Options Database Key:

-snes_monitor_ksp - Activates KSPMonitorSNESResidual()

Level: intermediate

-seealso: , SNES, KSPMonitorSet(), KSPMonitorResidual(), KSPMonitorTrueResidualMaxNorm(), KSPMonitor(), SNESMonitor(), PetscViewerAndFormat()

External Links

PETSc Manual: Snes/KSPMonitorSNESResidual

source

PETSc.LibPETSc.KSPMonitorSNESResidualDrawLG — Method

KSPMonitorSNESResidualDrawLG(petsclib::PetscLibType,ksp::PetscKSP, n::PetscInt, rnorm::PetscReal, vf::PetscViewerAndFormat)

Plots the linear KSP residual norm and the SNES residual norm of a KSPSolve() called within a SNESSolve().

Collective

Input Parameters:

ksp - iterative context
n - iteration number
rnorm - 2-norm (preconditioned) residual value (may be estimated).
vf - The viewer context, created with KSPMonitorSNESResidualDrawLGCreate()

Options Database Key:

-snes_monitor_ksp draw::draw_lg - Activates KSPMonitorSNESResidualDrawLG()

Level: intermediate

-seealso: , KSPMonitorSet(), KSPMonitorTrueResidual(), SNESMonitor(), KSPMonitor(), KSPMonitorSNESResidualDrawLGCreate()

External Links

PETSc Manual: Snes/KSPMonitorSNESResidualDrawLG

source

PETSc.LibPETSc.KSPMonitorSNESResidualDrawLGCreate — Method

vf::PetscViewerAndFormat = KSPMonitorSNESResidualDrawLGCreate(petsclib::PetscLibType,viewer::PetscViewer, format::PetscViewerFormat, ctx::Cvoid)

Creates the PetscViewer used by KSPMonitorSNESResidualDrawLG()

Collective

Input Parameters:

viewer - The PetscViewer
format - The viewer format
ctx - An optional user context

Output Parameter:

vf - The viewer context

Level: intermediate

-seealso: , KSP, SNES, PetscViewerFormat, PetscViewerAndFormat, KSPMonitorSet(), KSPMonitorTrueResidual()

External Links

PETSc Manual: Snes/KSPMonitorSNESResidualDrawLGCreate

source

PETSc.LibPETSc.KSPMonitorSet — Method

KSPMonitorSet(petsclib::PetscLibType,ksp::PetscKSP, monitor::KSPMonitorFn, ctx::Cvoid, monitordestroy::PetscCtxDestroyFn)

Sets an ADDITIONAL function to be called at every iteration to monitor, i.e. display in some way, perhaps by printing in the terminal, the residual norm computed in a KSPSolve()

Logically Collective

Input Parameters:

ksp - iterative solver obtained from KSPCreate()
monitor - pointer to function (if this is NULL, it turns off monitoring, see KSPMonitorFn
ctx - [optional] context for private data for the monitor routine (use NULL if no context is needed)
monitordestroy - [optional] routine that frees monitor context (may be NULL), see PetscCtxDestroyFn for the calling sequence

Options Database Keys:

-ksp_monitor - sets KSPMonitorResidual()
-ksp_monitor hdf5:filename - sets KSPMonitorResidualView() and saves residual
-ksp_monitor draw - sets KSPMonitorResidualView() and plots residual
-ksp_monitor draw::draw_lg - sets KSPMonitorResidualDrawLG() and plots residual
-ksp_monitor_pause_final - Pauses any graphics when the solve finishes (only works for internal monitors)
-ksp_monitor_true_residual - sets KSPMonitorTrueResidual()
-ksp_monitor_true_residual draw::draw_lg - sets KSPMonitorTrueResidualDrawLG() and plots residual
-ksp_monitor_max - sets KSPMonitorTrueResidualMax()
-ksp_monitor_singular_value - sets KSPMonitorSingularValue()
-ksp_monitor_cancel - cancels all monitors that have been hardwired into a code by calls to KSPMonitorSet(), but

does not cancel those set via the options database.

Level: beginner

-seealso: , KSPMonitorResidual(), KSPMonitorRegister(), KSPMonitorCancel(), KSP, PetscCtxDestroyFn

External Links

PETSc Manual: KSP/KSPMonitorSet

source

PETSc.LibPETSc.KSPMonitorSetFromOptions — Method

KSPMonitorSetFromOptions(petsclib::PetscLibType,ksp::PetscKSP, opt::String, name::String, ctx::Cvoid)

Sets a monitor function and viewer appropriate for the type indicated by the user in the options database

Collective

Input Parameters:

ksp - KSP object you wish to monitor
opt - the command line option for this monitor
name - the monitor type one is seeking
ctx - An optional user context for the monitor, or NULL

Level: developer

-seealso: , KSPMonitorRegister(), KSPMonitorSet(), PetscOptionsCreateViewer(), PetscOptionsGetReal(), PetscOptionsHasName(), PetscOptionsGetString(), PetscOptionsGetIntArray(), PetscOptionsGetRealArray(), PetscOptionsBool() PetscOptionsInt(), PetscOptionsString(), PetscOptionsReal(), PetscOptionsName(), PetscOptionsBegin(), PetscOptionsEnd(), PetscOptionsHeadBegin(), PetscOptionsStringArray(), PetscOptionsRealArray(), PetscOptionsScalar(), PetscOptionsBoolGroupBegin(), PetscOptionsBoolGroup(), PetscOptionsBoolGroupEnd(), PetscOptionsFList(), PetscOptionsEList()

External Links

PETSc Manual: KSP/KSPMonitorSetFromOptions

source

PETSc.LibPETSc.KSPMonitorSingularValue — Method

KSPMonitorSingularValue(petsclib::PetscLibType,ksp::PetscKSP, n::PetscInt, rnorm::PetscReal, vf::PetscViewerAndFormat)

Prints the two norm of the true residual and estimation of the extreme singular values of the preconditioned problem at each iteration.

Logically Collective

Input Parameters:

ksp - the iterative context
n - the iteration
rnorm - the two norm of the residual
vf - The viewer context

Options Database Key:

-ksp_monitor_singular_value - Activates KSPMonitorSingularValue()

Level: intermediate

-seealso: , KSP, KSPMonitorSet(), KSPComputeExtremeSingularValues(), KSPMonitorSingularValueCreate()

External Links

PETSc Manual: KSP/KSPMonitorSingularValue

source

PETSc.LibPETSc.KSPMonitorSingularValueCreate — Method

vf::PetscViewerAndFormat = KSPMonitorSingularValueCreate(petsclib::PetscLibType,viewer::PetscViewer, format::PetscViewerFormat, ctx::Cvoid)

Creates the singular value monitor context needed by KSPMonitorSingularValue()

Collective

Input Parameters:

viewer - The PetscViewer
format - The viewer format
ctx - An optional user context

Output Parameter:

vf - The viewer context

Level: intermediate

-seealso: , KSP, KSPMonitorSet(), KSPMonitorSingularValue(), PetscViewer

External Links

PETSc Manual: KSP/KSPMonitorSingularValueCreate

source

PETSc.LibPETSc.KSPMonitorSolution — Method

KSPMonitorSolution(petsclib::PetscLibType,ksp::PetscKSP, n::PetscInt, rnorm::PetscReal, vf::PetscViewerAndFormat)

Print the solution norm at each iteration of an iterative solver.

Collective

Input Parameters:

ksp - iterative context
n - iteration number
rnorm - 2-norm (preconditioned) residual value (may be estimated).
vf - The viewer context

Options Database Key:

-ksp_monitor_solution - Activates KSPMonitorSolution()

Level: intermediate

-seealso: , KSPMonitorSet(), KSPMonitorTrueResidual()

External Links

PETSc Manual: KSP/KSPMonitorSolution

source

PETSc.LibPETSc.KSPMonitorSolutionDraw — Method

KSPMonitorSolutionDraw(petsclib::PetscLibType,ksp::PetscKSP, n::PetscInt, rnorm::PetscReal, vf::PetscViewerAndFormat)

Plots the solution at each iteration of an iterative solver.

Collective

Input Parameters:

ksp - iterative context
n - iteration number
rnorm - 2-norm (preconditioned) residual value (may be estimated).
vf - The viewer context

Options Database Key:

-ksp_monitor_solution draw - Activates KSPMonitorSolutionDraw()

Level: intermediate

-seealso: , KSPMonitorSet(), KSPMonitorTrueResidual()

External Links

PETSc Manual: KSP/KSPMonitorSolutionDraw

source

PETSc.LibPETSc.KSPMonitorSolutionDrawLG — Method

KSPMonitorSolutionDrawLG(petsclib::PetscLibType,ksp::PetscKSP, n::PetscInt, rnorm::PetscReal, vf::PetscViewerAndFormat)

Plots the solution norm at each iteration of an iterative solver.

Collective

Input Parameters:

ksp - iterative context
n - iteration number
rnorm - 2-norm (preconditioned) residual value (may be estimated).
vf - The viewer context

Options Database Key:

-ksp_monitor_solution draw::draw_lg - Activates KSPMonitorSolutionDrawLG()

Level: intermediate

-seealso: , KSP, KSPMonitorSet(), KSPMonitorTrueResidual(), KSPMonitorSolutionDrawLGCreate()

External Links

PETSc Manual: KSP/KSPMonitorSolutionDrawLG

source

PETSc.LibPETSc.KSPMonitorSolutionDrawLGCreate — Method

vf::PetscViewerAndFormat = KSPMonitorSolutionDrawLGCreate(petsclib::PetscLibType,viewer::PetscViewer, format::PetscViewerFormat, ctx::Cvoid)

Creates the context for the KSP monitor KSPMonitorSolutionDrawLG()

Collective

Input Parameters:

viewer - The PetscViewer
format - The viewer format
ctx - An optional user context

Output Parameter:

vf - The viewer context

Level: intermediate

-seealso: , KSPMonitorSet(), KSPMonitorTrueResidual()

External Links

PETSc Manual: KSP/KSPMonitorSolutionDrawLGCreate

source

PETSc.LibPETSc.KSPMonitorTrueResidual — Method

KSPMonitorTrueResidual(petsclib::PetscLibType,ksp::PetscKSP, n::PetscInt, rnorm::PetscReal, vf::PetscViewerAndFormat)

Prints the true residual norm, as well as the (possibly preconditioned, possibly approximate) residual norm, at each iteration of a KSPSolve() iterative solver.

Collective

Input Parameters:

ksp - iterative context
n - iteration number
rnorm - 2-norm (preconditioned) residual value (may be estimated).
vf - The viewer context

Options Database Key:

-ksp_monitor_true_residual - Activates KSPMonitorTrueResidual() to print both norm values at each iteration

Level: intermediate

-seealso: , KSP, KSPMonitorSet(), KSPMonitorResidual(), KSPMonitorTrueResidualMaxNorm(), PetscViewerAndFormat

External Links

PETSc Manual: KSP/KSPMonitorTrueResidual

source

PETSc.LibPETSc.KSPMonitorTrueResidualDrawLG — Method

KSPMonitorTrueResidualDrawLG(petsclib::PetscLibType,ksp::PetscKSP, n::PetscInt, rnorm::PetscReal, vf::PetscViewerAndFormat)

Plots the true residual norm at each iteration of an iterative solver.

Collective

Input Parameters:

ksp - iterative context
n - iteration number
rnorm - 2-norm (preconditioned) residual value (may be estimated).
vf - The viewer context

Options Database Key:

-ksp_monitor_true_residual draw::draw_lg - Activates KSPMonitorTrueResidualDrawLG()

Level: intermediate

-seealso: , PETSCVIEWERDRAW, KSP, KSPMonitorSet(), KSPMonitorTrueResidual(), KSPMonitorTrueResidualDraw(), KSPMonitorResidual, KSPMonitorTrueResidualDrawLGCreate()

External Links

PETSc Manual: KSP/KSPMonitorTrueResidualDrawLG

source

PETSc.LibPETSc.KSPMonitorTrueResidualDrawLGCreate — Method

vf::PetscViewerAndFormat = KSPMonitorTrueResidualDrawLGCreate(petsclib::PetscLibType,viewer::PetscViewer, format::PetscViewerFormat, ctx::Cvoid)

Creates the context for the true residual monitor KSPMonitorTrueResidualDrawLG()

Collective

Input Parameters:

viewer - The PetscViewer of type PETSCVIEWERDRAW
format - The viewer format
ctx - An optional user context

Output Parameter:

vf - The viewer context

Level: intermediate

-seealso: , PETSCVIEWERDRAW, KSP, KSPMonitorSet(), KSPMonitorTrueResidual(), PetscViewerAndFormat

External Links

PETSc Manual: KSP/KSPMonitorTrueResidualDrawLGCreate

source

PETSc.LibPETSc.KSPMonitorTrueResidualMax — Method

KSPMonitorTrueResidualMax(petsclib::PetscLibType,ksp::PetscKSP, n::PetscInt, rnorm::PetscReal, vf::PetscViewerAndFormat)

Prints the true residual max norm at each iteration of an iterative solver.

Collective

Input Parameters:

ksp - iterative context
n - iteration number
rnorm - 2-norm (preconditioned) residual value (may be estimated).
vf - The viewer context

Options Database Key:

-ksp_monitor_true_residual_max - Activates KSPMonitorTrueResidualMax()

Level: intermediate

-seealso: , KSP, KSPMonitorSet(), KSPMonitorResidual(), KSPMonitorTrueResidualMaxNorm()

External Links

PETSc Manual: KSP/KSPMonitorTrueResidualMax

source

PETSc.LibPETSc.KSPMonitorTrueResidualView — Method

KSPMonitorTrueResidualView(petsclib::PetscLibType,ksp::PetscKSP, n::PetscInt, rnorm::PetscReal, vf::PetscViewerAndFormat)

Plots the true residual at each iteration of an iterative solver.

Collective

Input Parameters:

ksp - iterative context
n - iteration number
rnorm - 2-norm (preconditioned) residual value (may be estimated).
vf - The viewer context of type PETSCVIEWERDRAW

Options Database Key:

-ksp_monitor_true_residual viewertype - Activates KSPMonitorTrueResidualView()

Level: intermediate

-seealso: , PETSCVIEWERDRAW, KSP, KSPMonitorSet(), KSPMonitorTrueResidual(), KSPMonitorResidual(), KSPMonitorTrueResidualDrawLG(), PetscViewerAndFormat

External Links

PETSc Manual: KSP/KSPMonitorTrueResidualView

source

PETSc.LibPETSc.KSPPIPEFCGGetMmax — Method

mmax::PetscInt = KSPPIPEFCGGetMmax(petsclib::PetscLibType,ksp::PetscKSP)

get the maximum number of previous directions KSPPIPEFCG will store

Not Collective

Input Parameter:

ksp - the Krylov space context

Output Parameter:

mmax - the maximum number of previous directions allowed for orthogonalization

Level: intermediate

-seealso: , KSPPIPEFCG, KSPPIPEFCGGetTruncationType(), KSPPIPEFCGGetNprealloc(), KSPPIPEFCGSetMmax(), KSPFCGGetMmax(), KSPFCGSetMmax()

External Links

PETSc Manual: KSP/KSPPIPEFCGGetMmax

source

PETSc.LibPETSc.KSPPIPEFCGGetNprealloc — Method

nprealloc::PetscInt = KSPPIPEFCGGetNprealloc(petsclib::PetscLibType,ksp::PetscKSP)

get the number of directions to preallocate by KSPPIPEFCG

Not Collective

Input Parameter:

ksp - the Krylov space context

Output Parameter:

nprealloc - the number of directions preallocated

Level: advanced

-seealso: , KSPPIPEFCG, KSPPIPEFCGGetTruncationType(), KSPPIPEFCGSetNprealloc(), KSPPIPEFCGSetMmax(), KSPPIPEFCGGetMmax()

External Links

PETSc Manual: KSP/KSPPIPEFCGGetNprealloc

source

PETSc.LibPETSc.KSPPIPEFCGGetTruncationType — Method

truncstrat::KSPFCDTruncationType = KSPPIPEFCGGetTruncationType(petsclib::PetscLibType,ksp::PetscKSP)

get the truncation strategy employed by KSPPIPEFCG

Not Collective

Input Parameter:

ksp - the Krylov space context

Output Parameter:

truncstrat - the strategy type

Level: intermediate

-seealso: , KSPPIPEFCG, KSPPIPEFCGSetTruncationType, KSPFCDTruncationType, KSP_FCD_TRUNC_TYPE_STANDARD, KSP_FCD_TRUNC_TYPE_NOTAY

External Links

PETSc Manual: KSP/KSPPIPEFCGGetTruncationType

source

PETSc.LibPETSc.KSPPIPEFCGSetMmax — Method

KSPPIPEFCGSetMmax(petsclib::PetscLibType,ksp::PetscKSP, mmax::PetscInt)

set the maximum number of previous directions KSPPIPEFCG will store for orthogonalization

Logically Collective

Input Parameters:

ksp - the Krylov space context
mmax - the maximum number of previous directions to orthogonalize against

Options Database Key:

-ksp_pipefcg_mmax <N> - maximum number of previous directions

Level: intermediate

-seealso: , KSPPIPEFCG, KSPPIPEFCGSetTruncationType(), KSPPIPEFCGSetNprealloc(), KSPFCGSetMmax(), KSPFCGGetMmax()

External Links

PETSc Manual: KSP/KSPPIPEFCGSetMmax

source

PETSc.LibPETSc.KSPPIPEFCGSetNprealloc — Method

KSPPIPEFCGSetNprealloc(petsclib::PetscLibType,ksp::PetscKSP, nprealloc::PetscInt)

set the number of directions to preallocate with KSPPIPEFCG

Logically Collective

Input Parameters:

ksp - the Krylov space context
nprealloc - the number of vectors to preallocate

Options Database Key:

-ksp_pipefcg_nprealloc <N> - the number of vectors to preallocate

Level: advanced

-seealso: , KSPPIPEFCG, KSPPIPEFCGSetTruncationType(), KSPPIPEFCGGetNprealloc(), KSPPIPEFCGSetMmax(), KSPPIPEFCGGetMmax()

External Links

PETSc Manual: KSP/KSPPIPEFCGSetNprealloc

source

PETSc.LibPETSc.KSPPIPEFCGSetTruncationType — Method

KSPPIPEFCGSetTruncationType(petsclib::PetscLibType,ksp::PetscKSP, truncstrat::KSPFCDTruncationType)

specify how many of its stored previous directions KSPPIPEFCG uses during orthoganalization

Logically Collective

Input Parameters:

ksp - the Krylov space context
truncstrat - the choice of strategy

-seealso: , KSPPIPEFCG, KSPPIPEFCGGetTruncationType, KSPFCDTruncationType, KSP_FCD_TRUNC_TYPE_STANDARD, KSP_FCD_TRUNC_TYPE_NOTAY

External Links

PETSc Manual: KSP/KSPPIPEFCGSetTruncationType

source

PETSc.LibPETSc.KSPPIPEFGMRESSetShift — Method

KSPPIPEFGMRESSetShift(petsclib::PetscLibType,ksp::PetscKSP, shift::PetscScalar)

Set the shift parameter for the flexible, pipelined KSPPIPEFGMRES solver.

Logically Collective

Input Parameters:

ksp - the Krylov space context
shift - the shift

Options Database Key:

-ksp_pipefgmres_shift <shift> - set the shift parameter

Level: intermediate

-seealso: , KSPPIPEFGMRES, KSPComputeEigenvalues()

External Links

PETSc Manual: KSP/KSPPIPEFGMRESSetShift

source

PETSc.LibPETSc.KSPPIPEGCRGetMmax — Method

mmax::PetscInt = KSPPIPEGCRGetMmax(petsclib::PetscLibType,ksp::PetscKSP)

get the maximum number of previous directions KSPPIPEGCR will store

Not Collective

Input Parameter:

ksp - the Krylov space context

Output Parameter:

mmax - the maximum number of previous directions allowed for orthogonalization

Level: intermediate

-seealso: , KSPPIPEGCR, KSPPIPEGCRGetTruncationType(), KSPPIPEGCRGetNprealloc(), KSPPIPEGCRSetMmax()

External Links

PETSc Manual: KSP/KSPPIPEGCRGetMmax

source

PETSc.LibPETSc.KSPPIPEGCRGetNprealloc — Method

nprealloc::PetscInt = KSPPIPEGCRGetNprealloc(petsclib::PetscLibType,ksp::PetscKSP)

get the number of directions preallocate by KSPPIPEGCR

Not Collective

Input Parameter:

ksp - the Krylov space context

Output Parameter:

nprealloc - the number of directions preallocated

Level: advanced

-seealso: , KSPPIPEGCR, KSPPIPEGCRGetTruncationType(), KSPPIPEGCRSetNprealloc()

External Links

PETSc Manual: KSP/KSPPIPEGCRGetNprealloc

source

PETSc.LibPETSc.KSPPIPEGCRGetTruncationType — Method

truncstrat::KSPFCDTruncationType = KSPPIPEGCRGetTruncationType(petsclib::PetscLibType,ksp::PetscKSP)

get the truncation strategy employed by KSPPIPEGCR

Not Collective

Input Parameter:

ksp - the Krylov space context

Output Parameter:

truncstrat - the strategy type

-seealso: , KSPPIPEGCR, KSPPIPEGCRSetTruncationType, KSPPIPEGCRTruncationType, KSPFCDTruncationType, KSP_FCD_TRUNC_TYPE_STANDARD, KSP_FCD_TRUNC_TYPE_NOTAY

External Links

PETSc Manual: KSP/KSPPIPEGCRGetTruncationType

source

PETSc.LibPETSc.KSPPIPEGCRGetUnrollW — Method

unroll_w::PetscBool = KSPPIPEGCRGetUnrollW(petsclib::PetscLibType,ksp::PetscKSP)

Get information on KSPPIPEGCR if it uses unrolling the w vector

Logically Collective

Input Parameter:

ksp - the Krylov space context

Output Parameter:

unroll_w - KSPPIPEGCR uses unrolling (bool)

Level: intermediate

-seealso: , KSPPIPEGCR, KSPPIPEGCRGetTruncationType(), KSPPIPEGCRGetNprealloc(), KSPPIPEGCRSetUnrollW()

External Links

PETSc Manual: KSP/KSPPIPEGCRGetUnrollW

source

PETSc.LibPETSc.KSPPIPEGCRSetMmax — Method

KSPPIPEGCRSetMmax(petsclib::PetscLibType,ksp::PetscKSP, mmax::PetscInt)

set the maximum number of previous directions KSPPIPEGCR will store for orthogonalization

Logically Collective

Input Parameters:

ksp - the Krylov space context
mmax - the maximum number of previous directions to orthogonalize against

Options Database Key:

-ksp_pipegcr_mmax <mmax> - maximum number of previous directions

Level: intermediate

-seealso: , KSPPIPEGCR, KSPPIPEGCRSetTruncationType(), KSPPIPEGCRSetNprealloc()

External Links

PETSc Manual: KSP/KSPPIPEGCRSetMmax

source

PETSc.LibPETSc.KSPPIPEGCRSetModifyPC — Method

KSPPIPEGCRSetModifyPC(petsclib::PetscLibType,ksp::PetscKSP, fnc::KSPFlexibleModifyPCFn, ctx::Cvoid, destroy::PetscCtxDestroyFn)

Sets the routine used by KSPPIPEGCR to modify the preconditioner at each iteration

Logically Collective

Input Parameters:

ksp - iterative context obtained from KSPCreate()
function - user defined function to modify the preconditioner, see KSPFlexibleModifyPCFn
ctx - user provided context for the modify preconditioner function
destroy - the function to use to destroy the user provided application context.

Level: intermediate

-seealso: , KSPFlexibleSetModifyPC(), KSPFlexibleModifyPCFn, KSPPIPEGCR

External Links

PETSc Manual: KSP/KSPPIPEGCRSetModifyPC

source

PETSc.LibPETSc.KSPPIPEGCRSetNprealloc — Method

KSPPIPEGCRSetNprealloc(petsclib::PetscLibType,ksp::PetscKSP, nprealloc::PetscInt)

set the number of directions to preallocate with KSPPIPEGCR

Logically Collective

Input Parameters:

ksp - the Krylov space context
nprealloc - the number of vectors to preallocate

Level: advanced

Options Database Key:

-ksp_pipegcr_nprealloc <N> - number of vectors to preallocate

-seealso: , KSPPIPEGCR, KSPPIPEGCRGetTruncationType(), KSPPIPEGCRGetNprealloc()

External Links

PETSc Manual: KSP/KSPPIPEGCRSetNprealloc

source

PETSc.LibPETSc.KSPPIPEGCRSetTruncationType — Method

KSPPIPEGCRSetTruncationType(petsclib::PetscLibType,ksp::PetscKSP, truncstrat::KSPFCDTruncationType)

specify how many of its stored previous directions KSPPIPEGCR uses during orthogonalization

Logically Collective

Input Parameters:

ksp - the Krylov space context
truncstrat - the choice of strategy

-seealso: , KSPPIPEGCR, KSPPIPEGCRTruncationType, KSPFCDTruncationType, KSP_FCD_TRUNC_TYPE_STANDARD, KSP_FCD_TRUNC_TYPE_NOTAY

External Links

PETSc Manual: KSP/KSPPIPEGCRSetTruncationType

source

PETSc.LibPETSc.KSPPIPEGCRSetUnrollW — Method

KSPPIPEGCRSetUnrollW(petsclib::PetscLibType,ksp::PetscKSP, unroll_w::PetscBool)

Set to PETSC_TRUE to use KSPPIPEGCR with unrolling of the w vector

Logically Collective

Input Parameters:

ksp - the Krylov space context
unroll_w - use unrolling

Level: intermediate

Options Database Key:

-ksp_pipegcr_unroll_w <bool> - use unrolling

-seealso: , KSPPIPEGCR, KSPPIPEGCRSetTruncationType(), KSPPIPEGCRSetNprealloc(), KSPPIPEGCRGetUnrollW()

External Links

PETSc Manual: KSP/KSPPIPEGCRSetUnrollW

source

PETSc.LibPETSc.KSPPythonGetType — Method

pyname::String = KSPPythonGetType(petsclib::PetscLibType,ksp::PetscKSP)

Get the type of a KSP object implemented in Python.

Not Collective

Input Parameter:

ksp - the linear solver KSP context.

Output Parameter:

pyname - full dotted Python name [package].module[.{class|function}]

Level: intermediate

-seealso: , KSPCreate(), KSPSetType(), KSPPYTHON, PetscPythonInitialize(), KSPPythonSetType()

External Links

PETSc Manual: KSP/KSPPythonGetType

source

PETSc.LibPETSc.KSPPythonSetType — Method

KSPPythonSetType(petsclib::PetscLibType,ksp::PetscKSP, pyname::String)

Initialize a KSP object to a type implemented in Python.

Collective

Input Parameters:

ksp - the linear solver KSP context.
pyname - full dotted Python name [package].module[.{class|function}]

Options Database Key:

-ksp_python_type <pyname> - python class

Level: intermediate

-seealso: , KSPCreate(), KSPSetType(), KSPPYTHON, PetscPythonInitialize()

External Links

PETSc Manual: KSP/KSPPythonSetType

source

PETSc.LibPETSc.KSPQCGGetQuadratic — Method

quadratic::PetscReal = KSPQCGGetQuadratic(petsclib::PetscLibType,ksp::PetscKSP)

Gets the value of the quadratic function, evaluated at the new iterate

Collective

Input Parameter:

ksp - the iterative context

Output Parameter:

quadratic - the quadratic function evaluated at the new iterate

Level: advanced

-seealso: , KSPQCG

External Links

PETSc Manual: KSP/KSPQCGGetQuadratic

source

PETSc.LibPETSc.KSPQCGGetTrialStepNorm — Method

tsnorm::PetscReal = KSPQCGGetTrialStepNorm(petsclib::PetscLibType,ksp::PetscKSP)

Gets the norm of a trial step vector in KSPQCG. The WCG step may be constrained, so this is not necessarily the length of the ultimate step taken in KSPQCG.

Not Collective

Input Parameter:

ksp - the iterative context

Output Parameter:

tsnorm - the norm

Level: advanced

-seealso: , KSPQCG, KSPQCGSetTrustRegionRadius()

External Links

PETSc Manual: KSP/KSPQCGGetTrialStepNorm

source

PETSc.LibPETSc.KSPQCGSetTrustRegionRadius — Method

KSPQCGSetTrustRegionRadius(petsclib::PetscLibType,ksp::PetscKSP, delta::PetscReal)

Sets the radius of the trust region for KSPQCG

Logically Collective

Input Parameters:

ksp - the iterative context
delta - the trust region radius (Infinity is the default)

Options Database Key:

-ksp_qcg_trustregionradius <delta> - trust region radius

Level: advanced

-seealso: , KSPQCG, KSPQCGGetTrialStepNorm()

External Links

PETSc Manual: KSP/KSPQCGSetTrustRegionRadius

source

PETSc.LibPETSc.KSPRegister — Method

KSPRegister(petsclib::PetscLibType,sname::String, fnc::external)

Adds a method, KSPType, to the Krylov subspace solver package.

Not Collective, No Fortran Support

Input Parameters:

sname - name of a new user-defined solver
function - routine to create method

Level: advanced

-seealso: , KSP, KSPType, KSPSetType, KSPRegisterAll()

External Links

PETSc Manual: KSP/KSPRegister

source

PETSc.LibPETSc.KSPReset — Method

KSPReset(petsclib::PetscLibType,ksp::PetscKSP)

Removes any allocated Vec and Mat from the KSP data structures.

Collective

Input Parameter:

ksp - iterative solver obtained from KSPCreate()

Level: intermediate

-seealso: , KSPCreate(), KSPSetUp(), KSPSolve(), KSP

External Links

PETSc Manual: KSP/KSPReset

source

PETSc.LibPETSc.KSPResetFromOptions — Method

KSPResetFromOptions(petsclib::PetscLibType,ksp::PetscKSP)

Sets KSP parameters from user options ONLY if the KSP was previously set from options

Collective

Input Parameter:

ksp - the KSP context

Level: advanced

-seealso: , KSPSetFromOptions(), KSPSetOptionsPrefix()

External Links

PETSc Manual: KSP/KSPResetFromOptions

source

PETSc.LibPETSc.KSPResetViewers — Method

KSPResetViewers(petsclib::PetscLibType,ksp::PetscKSP)

Resets all the viewers set from the options database during KSPSetFromOptions()

Collective

Input Parameter:

ksp - the KSP iterative solver context obtained from KSPCreate()

Level: beginner

-seealso: , KSPCreate(), KSPSetUp(), KSPSolve(), KSPSetFromOptions(), KSP

External Links

PETSc Manual: KSP/KSPResetViewers

source

PETSc.LibPETSc.KSPRichardsonSetScale — Method

KSPRichardsonSetScale(petsclib::PetscLibType,ksp::PetscKSP, scale::PetscReal)

Set the damping factor; if this routine is not called, the factor defaults to 1.0.

Logically Collective

Input Parameters:

ksp - the iterative context
scale - the damping factor

Options Database Key:

-ksp_richardson_scale <scale> - Set the scale factor

Level: intermediate

-seealso: , KSPRICHARDSON, KSPRichardsonSetSelfScale()

External Links

PETSc Manual: KSP/KSPRichardsonSetScale

source

PETSc.LibPETSc.KSPRichardsonSetSelfScale — Method

KSPRichardsonSetSelfScale(petsclib::PetscLibType,ksp::PetscKSP, scale::PetscBool)

Sets Richardson to automatically determine optimal scaling at each iteration to minimize the 2 preconditioned residual

Logically Collective

Input Parameters:

ksp - the iterative context
scale - PETSC_TRUE or the default of PETSC_FALSE

Options Database Key:

-ksp_richardson_self_scale - Use self-scaling

Level: intermediate

-seealso: , KSPRICHARDSON, KSPRichardsonSetScale()

External Links

PETSc Manual: KSP/KSPRichardsonSetSelfScale

source

PETSc.LibPETSc.KSPSetApplicationContext — Method

KSPSetApplicationContext(petsclib::PetscLibType,ksp::PetscKSP, ctx::Cvoid)

Sets the optional user

Logically Collective

Input Parameters:

ksp - the KSP context
ctx - user context

Level: intermediate

-seealso: , KSP, KSPGetApplicationContext()

External Links

PETSc Manual: KSP/KSPSetApplicationContext

source

PETSc.LibPETSc.KSPSetCheckNormIteration — Method

KSPSetCheckNormIteration(petsclib::PetscLibType,ksp::PetscKSP, it::PetscInt)

Sets the first iteration at which the norm of the residual will be computed and used in the convergence test of KSPSolve() for the given KSP context

Logically Collective

Input Parameters:

ksp - Krylov solver context
it - use -1 to check at all iterations

Level: advanced

-seealso: , KSP, KSPSetUp(), KSPSolve(), KSPDestroy(), KSPConvergedSkip(), KSPSetNormType(), KSPSetLagNorm()

External Links

PETSc Manual: KSP/KSPSetCheckNormIteration

source

PETSc.LibPETSc.KSPSetComputeEigenvalues — Method

KSPSetComputeEigenvalues(petsclib::PetscLibType,ksp::PetscKSP, flg::PetscBool)

Sets a flag so that the extreme eigenvalues values will be calculated via a Lanczos or Arnoldi process as the linear system is solved.

Logically Collective

Input Parameters:

ksp - iterative solver obtained from KSPCreate()
flg - PETSC_TRUE or PETSC_FALSE

Level: advanced

-seealso: , KSPComputeEigenvalues(), KSPComputeEigenvaluesExplicitly(), KSP, KSPSetComputeRitz()

External Links

PETSc Manual: KSP/KSPSetComputeEigenvalues

source

PETSc.LibPETSc.KSPSetComputeInitialGuess — Method

KSPSetComputeInitialGuess(petsclib::PetscLibType,ksp::PetscKSP, func::Union{KSPComputeInitialGuessFn, Ptr}, ctx::Union{Cvoid, Ptr})

set routine to compute the initial guess of the linear system

Logically Collective

Input Parameters:

ksp - the KSP context
func - function to compute the initial guess, see KSPComputeInitialGuessFn for calling sequence
ctx - optional context

Level: beginner

-seealso: , KSP, KSPSolve(), KSPSetComputeRHS(), KSPSetComputeOperators(), DMKSPSetComputeInitialGuess(), KSPSetInitialGuessNonzero(), KSPComputeInitialGuessFn

External Links

PETSc Manual: KSP/KSPSetComputeInitialGuess

source

PETSc.LibPETSc.KSPSetComputeOperators — Method

KSPSetComputeOperators(petsclib::PetscLibType,ksp::PetscKSP, func::Union{KSPComputeOperatorsFn, Ptr}, ctx::Union{Cvoid, Ptr})

set routine to compute the linear operators

Logically Collective

Input Parameters:

ksp - the KSP context
func - function to compute the operators, see KSPComputeOperatorsFn for the calling sequence
ctx - optional context

Level: beginner

-seealso: , KSP, KSPSetOperators(), KSPSetComputeRHS(), DMKSPSetComputeOperators(), KSPSetComputeInitialGuess(), KSPComputeOperatorsFn

External Links

PETSc Manual: KSP/KSPSetComputeOperators

source

PETSc.LibPETSc.KSPSetComputeRHS — Method

KSPSetComputeRHS(petsclib::PetscLibType,ksp::PetscKSP, func::Union{KSPComputeRHSFn,Ptr}, ctx::Union{Cvoid, Ptr})

set routine to compute the right

Logically Collective

Input Parameters:

ksp - the KSP context
func - function to compute the right-hand side, see KSPComputeRHSFn for the calling sequence
ctx - optional context

Level: beginner

-seealso: , KSP, KSPSolve(), DMKSPSetComputeRHS(), KSPSetComputeOperators(), KSPSetOperators(), KSPComputeRHSFn

External Links

PETSc Manual: KSP/KSPSetComputeRHS

source

PETSc.LibPETSc.KSPSetComputeRitz — Method

KSPSetComputeRitz(petsclib::PetscLibType,ksp::PetscKSP, flg::PetscBool)

Sets a flag so that the Ritz or harmonic Ritz pairs will be calculated via a Lanczos or Arnoldi process as the linear system is solved.

Logically Collective

Input Parameters:

ksp - iterative solver obtained from KSPCreate()
flg - PETSC_TRUE or PETSC_FALSE

Level: advanced

-seealso: , KSPComputeRitz(), KSP, KSPComputeEigenvalues(), KSPComputeExtremeSingularValues()

External Links

PETSc Manual: KSP/KSPSetComputeRitz

source

PETSc.LibPETSc.KSPSetComputeSingularValues — Method

KSPSetComputeSingularValues(petsclib::PetscLibType,ksp::PetscKSP, flg::PetscBool)

Sets a flag so that the extreme singular values will be calculated via a Lanczos or Arnoldi process as the linear system is solved.

Logically Collective

Input Parameters:

ksp - iterative solver obtained from KSPCreate()
flg - PETSC_TRUE or PETSC_FALSE

Options Database Key:

-ksp_monitor_singular_value - Activates KSPSetComputeSingularValues()

Level: advanced

-seealso: , KSPComputeExtremeSingularValues(), KSPMonitorSingularValue(), KSP, KSPSetComputeRitz()

External Links

PETSc Manual: KSP/KSPSetComputeSingularValues

source

PETSc.LibPETSc.KSPSetConvergedNegativeCurvature — Method

KSPSetConvergedNegativeCurvature(petsclib::PetscLibType,ksp::PetscKSP, flg::PetscBool)

Allows to declare convergence and return KSP_CONVERGED_NEG_CURVE when negative curvature is detected

Collective

Input Parameters:

ksp - iterative context
flg - the Boolean value

Options Database Key:

-ksp_converged_neg_curve <bool> - Declare convergence if negative curvature is detected

Level: advanced

-seealso: , KSP, KSPConvergedReason, KSPGetConvergedNegativeCurvature()

External Links

PETSc Manual: KSP/KSPSetConvergedNegativeCurvature

source

PETSc.LibPETSc.KSPSetConvergenceTest — Method

KSPSetConvergenceTest(petsclib::PetscLibType,ksp::PetscKSP, converge::KSPConvergenceTestFn, ctx::Cvoid, destroy::PetscCtxDestroyFn)

Sets the function to be used to determine convergence of KSPSolve()

Logically Collective

Input Parameters:

ksp - iterative solver obtained from KSPCreate()
converge - pointer to the function, see KSPConvergenceTestFn
ctx - context for private data for the convergence routine (may be NULL)
destroy - a routine for destroying the context (may be NULL)

Level: advanced

-seealso: , KSP, KSPConvergenceTestFn, KSPConvergedDefault(), KSPGetConvergenceContext(), KSPSetTolerances(), KSPGetConvergenceTest(), KSPGetAndClearConvergenceTest()

External Links

PETSc Manual: KSP/KSPSetConvergenceTest

source

PETSc.LibPETSc.KSPSetDM — Method

KSPSetDM(petsclib::PetscLibType,ksp::PetscKSP, dm::PetscDM)

Sets the DM that may be used by some preconditioners and that may be used to construct the linear system

Logically Collective

Input Parameters:

ksp - the KSP
dm - the DM, cannot be NULL to remove a previously set DM

Level: intermediate

-seealso: , KSP, DM, KSPGetDM(), KSPSetDMActive(), KSPSetComputeOperators(), KSPSetComputeRHS(), KSPSetComputeInitialGuess(), DMKSPSetComputeOperators(), DMKSPSetComputeRHS(), DMKSPSetComputeInitialGuess()

External Links

PETSc Manual: KSP/KSPSetDM

source

PETSc.LibPETSc.KSPSetDMActive — Method

KSPSetDMActive(petsclib::PetscLibType,ksp::PetscKSP, flg::PetscBool)

Indicates the DM should be used to generate the linear system matrix and right

Logically Collective

Input Parameters:

ksp - the KSP
flg - use the DM

Level: intermediate

-seealso: , KSP, DM, KSPGetDM(), KSPSetDM(), SNESSetDM(), KSPSetComputeOperators(), KSPSetComputeRHS(), KSPSetComputeInitialGuess()

External Links

PETSc Manual: KSP/KSPSetDMActive

source

PETSc.LibPETSc.KSPSetDiagonalScale — Method

KSPSetDiagonalScale(petsclib::PetscLibType,ksp::PetscKSP, scale::PetscBool)

Tells KSP to symmetrically diagonally scale the system before solving. This actually CHANGES the matrix (and right-hand side).

Logically Collective

Input Parameters:

ksp - the KSP context
scale - PETSC_TRUE or PETSC_FALSE

Options Database Keys:

-ksp_diagonal_scale - perform a diagonal scaling before the solve
-ksp_diagonal_scale_fix - scale the matrix back AFTER the solve

Level: advanced

-seealso: , KSPGetDiagonalScale(), KSPSetDiagonalScaleFix(), KSP

External Links

PETSc Manual: KSP/KSPSetDiagonalScale

source

PETSc.LibPETSc.KSPSetDiagonalScaleFix — Method

KSPSetDiagonalScaleFix(petsclib::PetscLibType,ksp::PetscKSP, fix::PetscBool)

Tells KSP to diagonally scale the system back after solving.

Logically Collective

Input Parameters:

ksp - the KSP context
fix - PETSC_TRUE to scale back after the system solve, PETSC_FALSE to not

rescale (default)

Level: intermediate

-seealso: , KSPGetDiagonalScale(), KSPSetDiagonalScale(), KSPGetDiagonalScaleFix(), KSP

External Links

PETSc Manual: KSP/KSPSetDiagonalScaleFix

source

PETSc.LibPETSc.KSPSetErrorHistory — Method

KSPSetErrorHistory(petsclib::PetscLibType,ksp::PetscKSP, a::Vector{PetscReal}, na::PetscCount, reset::PetscBool)

Sets the array used to hold the error history. If set, this array will contain the error norms computed at each iteration of the solver.

Not Collective

Input Parameters:

ksp - iterative solver obtained from KSPCreate()
a - array to hold history
na - size of a
reset - PETSC_TRUE indicates the history counter is reset to zero for each new linear solve

Level: advanced

-seealso: , KSPGetErrorHistory(), KSPSetResidualHistory(), KSP

External Links

PETSc Manual: KSP/KSPSetErrorHistory

source

PETSc.LibPETSc.KSPSetErrorIfNotConverged — Method

KSPSetErrorIfNotConverged(petsclib::PetscLibType,ksp::PetscKSP, flg::PetscBool)

Causes KSPSolve() to generate an error if the solver has not converged as soon as the error is detected.

Logically Collective

Input Parameters:

ksp - iterative solver obtained from KSPCreate()
flg - PETSC_TRUE indicates you want the error generated

Options Database Key:

-ksp_error_if_not_converged <true,false> - generate an error and stop the program

Level: intermediate

-seealso: , KSPGetErrorIfNotConverged(), KSP

External Links

PETSc Manual: KSP/KSPSetErrorIfNotConverged

source

PETSc.LibPETSc.KSPSetFromOptions — Method

KSPSetFromOptions(petsclib::PetscLibType,ksp::PetscKSP)

Sets KSP options from the options database. This routine must be called before KSPSetUp() if the user is to be allowed to set the Krylov type.

Collective

Input Parameter:

ksp - the Krylov space context

Options Database Keys:

-ksp_rtol rtol - relative tolerance used in default determination of convergence, i.e.

if residual norm decreases by this factor than convergence is declared

-ksp_atol abstol - absolute tolerance used in default convergence test, i.e. if residual

norm is less than this then convergence is declared

-ksp_divtol tol - if residual norm increases by this factor than divergence is declared
-ksp_max_it - maximum number of linear iterations
-ksp_min_it - minimum number of linear iterations to use, defaults to zero
-ksp_reuse_preconditioner <true,false> - reuse the previously computed preconditioner
-ksp_converged_use_initial_residual_norm - see KSPConvergedDefaultSetUIRNorm()
-ksp_converged_use_min_initial_residual_norm - see KSPConvergedDefaultSetUMIRNorm()
-ksp_converged_maxits - see KSPConvergedDefaultSetConvergedMaxits()
-ksp_norm_type <none,preconditioned,unpreconditioned,natural> - see KSPSetNormType()
-ksp_check_norm_iteration it - do not compute residual norm until iteration number it (does compute at 0th iteration)

works only for KSPBCGS, KSPIBCGS, and KSPCG

-ksp_lag_norm - compute the norm of the residual for the ith iteration on the i+1 iteration;

this means that one can use the norm of the residual for convergence test WITHOUT an extra MPI_Allreduce() limiting global synchronizations. This will require 1 more iteration of the solver than usual.

-ksp_guess_type - Type of initial guess generator for repeated linear solves
-ksp_fischer_guess <model,size> - uses the Fischer initial guess generator for repeated linear solves
-ksp_constant_null_space - assume the operator (matrix) has the constant vector in its null space
-ksp_test_null_space - tests the null space set with MatSetNullSpace() to see if it truly is a null space
-ksp_knoll - compute initial guess by applying the preconditioner to the right-hand side
-ksp_monitor_cancel - cancel all previous convergene monitor routines set
-ksp_monitor - print residual norm at each iteration
-ksp_monitor draw::draw_lg - plot residual norm at each iteration, see KSPMonitorResidual()
-ksp_monitor_true_residual - print the true l2 residual norm at each iteration, see KSPMonitorTrueResidual()
-all_ksp_monitor <optional filename> - print residual norm at each iteration for ALL KSP solves, regardless of their prefix. This is

useful for PCFIELDSPLIT, PCMG, etc that have inner solvers and you wish to track the convergence of all the solvers

-ksp_monitor_solution [ascii binary or draw][:filename][:format option] - plot solution at each iteration
-ksp_monitor_singular_value - monitor extreme singular values at each iteration
-ksp_converged_reason - view the convergence state at the end of the solve
-ksp_use_explicittranspose - transpose the system explicitly in KSPSolveTranspose()
-ksp_error_if_not_converged - stop the program as soon as an error is detected in a KSPSolve(), KSP_DIVERGED_ITS

is not treated as an error on inner solves

-ksp_converged_rate - view the convergence rate at the end of the solve

Level: beginner

-seealso: , KSP, KSPSetOptionsPrefix(), KSPResetFromOptions(), KSPSetUseFischerGuess()

External Links

PETSc Manual: KSP/KSPSetFromOptions

source

PETSc.LibPETSc.KSPSetGuess — Method

KSPSetGuess(petsclib::PetscLibType,ksp::PetscKSP, guess::KSPGuess)

Set the initial guess object KSPGuess to be used by the KSP object to generate initial guesses

Logically Collective

Input Parameters:

ksp - the Krylov context
guess - the object created with KSPGuessCreate()

Level: advanced

-seealso: , KSP, KSPGuess, KSPSetOptionsPrefix(), KSPAppendOptionsPrefix(), KSPSetUseFischerGuess(), KSPGetGuess()

External Links

PETSc Manual: KSP/KSPSetGuess

source

PETSc.LibPETSc.KSPSetInitialGuessKnoll — Method

KSPSetInitialGuessKnoll(petsclib::PetscLibType,ksp::PetscKSP, flg::PetscBool)

Tells the iterative solver to use PCApply() on the right hand side vector to compute the initial guess (The Knoll trick)

Logically Collective

Input Parameters:

ksp - iterative solver obtained from KSPCreate()
flg - PETSC_TRUE or PETSC_FALSE

Level: advanced

-seealso: , KSPGetInitialGuessKnoll(), KSPGuess, KSPSetInitialGuessNonzero(), KSPGetInitialGuessNonzero(), KSP

External Links

PETSc Manual: KSP/KSPSetInitialGuessKnoll

source

PETSc.LibPETSc.KSPSetInitialGuessNonzero — Method

KSPSetInitialGuessNonzero(petsclib::PetscLibType,ksp::PetscKSP, flg::PetscBool)

Tells the iterative solver that the initial guess is nonzero; otherwise KSP assumes the initial guess is to be zero (and thus zeros it out before solving).

Logically Collective

Input Parameters:

ksp - iterative solver obtained from KSPCreate()
flg - PETSC_TRUE indicates the guess is non-zero, PETSC_FALSE indicates the guess is zero

Options Database Key:

-ksp_initial_guess_nonzero <true,false> - use nonzero initial guess

Level: beginner

-seealso: , KSPGetInitialGuessNonzero(), KSPGuessSetType(), KSPGuessType, KSP

External Links

PETSc Manual: KSP/KSPSetInitialGuessNonzero

source

PETSc.LibPETSc.KSPSetLagNorm — Method

KSPSetLagNorm(petsclib::PetscLibType,ksp::PetscKSP, flg::PetscBool)

Lags the residual norm calculation so that it is computed as part of the MPI_Allreduce() used for computing the inner products needed for the next iteration.

Logically Collective

Input Parameters:

ksp - Krylov solver context
flg - PETSC_TRUE or PETSC_FALSE

Options Database Key:

-ksp_lag_norm - lag the calculated residual norm

Level: advanced

-seealso: , KSPSetUp(), KSPSolve(), KSPDestroy(), KSPConvergedSkip(), KSPSetNormType(), KSPSetCheckNormIteration()

External Links

PETSc Manual: KSP/KSPSetLagNorm

source

PETSc.LibPETSc.KSPSetMatSolveBatchSize — Method

KSPSetMatSolveBatchSize(petsclib::PetscLibType,ksp::PetscKSP, bs::PetscInt)

Sets the maximum number of columns treated simultaneously in KSPMatSolve().

Logically Collective

Input Parameters:

ksp - the KSP iterative solver
bs - batch size

Level: advanced

-seealso: , KSPMatSolve(), KSPGetMatSolveBatchSize(), -mat_mumps_icntl_27, -matmatmult_Bbn

External Links

PETSc Manual: KSP/KSPSetMatSolveBatchSize

source

PETSc.LibPETSc.KSPSetMinimumIterations — Method

KSPSetMinimumIterations(petsclib::PetscLibType,ksp::PetscKSP, minit::PetscInt)

Sets the minimum number of iterations to use, regardless of the tolerances

Logically Collective

Input Parameters:

ksp - the Krylov subspace context
minit - minimum number of iterations to use

Options Database Key:

-ksp_min_it <minits> - Sets minit

Level: intermediate

-seealso: , KSPGetTolerances(), KSPConvergedDefault(), KSPSetConvergenceTest(), KSP, KSPSetTolerances(), KSPGetMinimumIterations()

External Links

PETSc Manual: KSP/KSPSetMinimumIterations

source

PETSc.LibPETSc.KSPSetNestLevel — Method

KSPSetNestLevel(petsclib::PetscLibType,ksp::PetscKSP, level::PetscInt)

sets the amount of nesting the KSP has. That is the number of levels of KSP above this KSP in a linear solve.

Collective

Input Parameters:

ksp - the KSP
level - the nest level

Level: developer

-seealso: , KSPSetUp(), KSPSolve(), KSPDestroy(), KSP, KSPGMRES, KSPType, KSPGetNestLevel(), PCSetKSPNestLevel(), PCGetKSPNestLevel()

External Links

PETSc Manual: KSP/KSPSetNestLevel

source

PETSc.LibPETSc.KSPSetNormType — Method

KSPSetNormType(petsclib::PetscLibType,ksp::PetscKSP, normtype::KSPNormType)

Sets the type of residual norm that is used for convergence testing in KSPSolve() for the given KSP context

Logically Collective

Input Parameters:

ksp - Krylov solver context
normtype - one of

-seealso: , KSPSetUp(), KSPSolve(), KSPDestroy(), KSPConvergedSkip(), KSPSetCheckNormIteration(), KSPSetPCSide(), KSPGetPCSide(), KSPNormType

External Links

PETSc Manual: KSP/KSPSetNormType

source

PETSc.LibPETSc.KSPSetOperators — Method

KSPSetOperators(petsclib::PetscLibType,ksp::PetscKSP, Amat::PetscMat, Pmat::PetscMat)

Sets the matrix associated with the linear system and a (possibly) different one from which the preconditioner will be built into the KSP context. The matrix will then be used during KSPSolve()

Collective

Input Parameters:

ksp - the KSP context
Amat - the matrix that defines the linear system
Pmat - the matrix to be used in constructing the preconditioner, usually the same as Amat.

Level: beginner

-seealso: , KSP, Mat, KSPSolve(), KSPGetPC(), PCGetOperators(), PCSetOperators(), KSPGetOperators(), KSPSetComputeOperators(), KSPSetComputeInitialGuess(), KSPSetComputeRHS()

External Links

PETSc Manual: KSP/KSPSetOperators

source

PETSc.LibPETSc.KSPSetOptionsPrefix — Method

KSPSetOptionsPrefix(petsclib::PetscLibType,ksp::PetscKSP, prefix::String)

Sets the prefix used for searching for all KSP options in the database.

Logically Collective

Input Parameters:

ksp - the Krylov context
prefix - the prefix string to prepend to all KSP option requests

Level: intermediate

-seealso: , KSP, KSPAppendOptionsPrefix(), KSPGetOptionsPrefix(), KSPSetFromOptions()

External Links

PETSc Manual: KSP/KSPSetOptionsPrefix

source

PETSc.LibPETSc.KSPSetPC — Method

KSPSetPC(petsclib::PetscLibType,ksp::PetscKSP, pc::PC)

Sets the preconditioner to be used to calculate the application of the preconditioner on a vector into a KSP.

Collective

Input Parameters:

ksp - the KSP iterative solver obtained from KSPCreate()
pc - the preconditioner object (if NULL it returns the PC currently held by the KSP)

Level: developer

-seealso: , KSPGetPC(), KSP

External Links

PETSc Manual: KSP/KSPSetPC

source

PETSc.LibPETSc.KSPSetPCSide — Method

KSPSetPCSide(petsclib::PetscLibType,ksp::PetscKSP, side::PCSide)

Sets the preconditioning side.

Logically Collective

Input Parameter:

ksp - iterative solver obtained from KSPCreate()

Output Parameter:

side - the preconditioning side, where side is one of

-seealso: , KSPGetPCSide(), KSPSetNormType(), KSPGetNormType(), KSP, KSPSetPreSolve(), KSPSetPostSolve()

External Links

PETSc Manual: KSP/KSPSetPCSide

source

PETSc.LibPETSc.KSPSetPostSolve — Method

KSPSetPostSolve(petsclib::PetscLibType,ksp::PetscKSP, postsolve::KSPPSolveFn, ctx::Cvoid)

Sets a function that is called at the end of each KSPSolve() (whether it converges or not). Used in conjunction with KSPSetPreSolve().

Logically Collective

Input Parameters:

ksp - the solver object
postsolve - the function to call after the solve, seeKSPPSolveFn
ctx - an optional context needed by the function

Level: developer

-seealso: , KSPPSolveFn, KSPSetUp(), KSPSolve(), KSPDestroy(), KSP, KSPSetPreSolve(), PCEISENSTAT

External Links

PETSc Manual: KSP/KSPSetPostSolve

source

PETSc.LibPETSc.KSPSetPreSolve — Method

KSPSetPreSolve(petsclib::PetscLibType,ksp::PetscKSP, presolve::KSPPSolveFn, ctx::Cvoid)

Sets a function that is called at the beginning of each KSPSolve(). Used in conjunction with KSPSetPostSolve().

Logically Collective

Input Parameters:

ksp - the solver object
presolve - the function to call before the solve, seeKSPPSolveFn
ctx - an optional context needed by the function

Level: developer

-seealso: , KSPPSolveFn, KSPSetUp(), KSPSolve(), KSPDestroy(), KSP, KSPSetPostSolve(), PCEISENSTAT, PCPreSolve(), PCPostSolve()

External Links

PETSc Manual: KSP/KSPSetPreSolve

source

PETSc.LibPETSc.KSPSetResidualHistory — Method

KSPSetResidualHistory(petsclib::PetscLibType,ksp::PetscKSP, a::Vector{PetscReal}, na::PetscCount, reset::PetscBool)

Sets the array used to hold the residual history. If set, this array will contain the residual norms computed at each iteration of the solver.

Not Collective

Input Parameters:

ksp - iterative solver obtained from KSPCreate()
a - array to hold history
na - size of a
reset - PETSC_TRUE indicates the history counter is reset to zero

for each new linear solve

Level: advanced

-seealso: , KSPGetResidualHistory(), KSP

External Links

PETSc Manual: KSP/KSPSetResidualHistory

source

PETSc.LibPETSc.KSPSetReusePreconditioner — Method

KSPSetReusePreconditioner(petsclib::PetscLibType,ksp::PetscKSP, flag::PetscBool)

reuse the current preconditioner for future KSPSolve(), do not construct a new preconditioner even if the Mat operator in the KSP has different values

Collective

Input Parameters:

ksp - iterative solver obtained from KSPCreate()
flag - PETSC_TRUE to reuse the current preconditioner, or PETSC_FALSE to construct a new preconditioner

Options Database Key:

-ksp_reuse_preconditioner <true,false> - reuse the previously computed preconditioner

Level: intermediate

-seealso: , KSPCreate(), KSPSolve(), KSPDestroy(), KSP, KSPGetReusePreconditioner(), SNESSetLagPreconditioner(), SNES

External Links

PETSc Manual: KSP/KSPSetReusePreconditioner

source

PETSc.LibPETSc.KSPSetSkipPCSetFromOptions — Method

KSPSetSkipPCSetFromOptions(petsclib::PetscLibType,ksp::PetscKSP, flag::PetscBool)

prevents KSPSetFromOptions() from calling PCSetFromOptions(). This is used if the same PC is shared by more than one KSP so its options are not reset for each KSP

Collective

Input Parameters:

ksp - iterative solver obtained from KSPCreate()
flag - PETSC_TRUE to skip calling the PCSetFromOptions()

Level: developer

-seealso: , KSPCreate(), KSPSolve(), KSPDestroy(), PCSetReusePreconditioner(), KSP

External Links

PETSc Manual: KSP/KSPSetSkipPCSetFromOptions

source

PETSc.LibPETSc.KSPSetSupportedNorm — Method

KSPSetSupportedNorm(petsclib::PetscLibType,ksp::PetscKSP, normtype::KSPNormType, pcside::PCSide, priority::PetscInt)

Sets a norm and preconditioner side supported by a KSPType

Logically Collective

Input Parameters:

ksp - Krylov method
normtype - supported norm type of the type KSPNormType
pcside - preconditioner side, of the type PCSide that can be used with this KSPNormType
priority - positive integer preference for this combination; larger values have higher priority

Level: developer

-seealso: , KSP, KSPNormType, PCSide, KSPSetNormType(), KSPSetPCSide()

External Links

PETSc Manual: KSP/KSPSetSupportedNorm

source

PETSc.LibPETSc.KSPSetTolerances — Method

KSPSetTolerances(petsclib::PetscLibType,ksp::PetscKSP, rtol::PetscReal, abstol::PetscReal, dtol::PetscReal, maxits::PetscInt)

Sets the relative, absolute, divergence, and maximum iteration tolerances used by the default KSP convergence testers.

Logically Collective

Input Parameters:

ksp - the Krylov subspace context
rtol - the relative convergence tolerance, relative decrease in the (possibly preconditioned) residual norm
abstol - the absolute convergence tolerance absolute size of the (possibly preconditioned) residual norm
dtol - the divergence tolerance, amount (possibly preconditioned) residual norm can increase before KSPConvergedDefault() concludes that the method is diverging
maxits - maximum number of iterations to use

Options Database Keys:

-ksp_atol <abstol> - Sets abstol
-ksp_rtol <rtol> - Sets rtol
-ksp_divtol <dtol> - Sets dtol
-ksp_max_it <maxits> - Sets maxits

Level: intermediate

-seealso: , KSPGetTolerances(), KSPConvergedDefault(), KSPSetConvergenceTest(), KSP, KSPSetMinimumIterations()

External Links

PETSc Manual: KSP/KSPSetTolerances

source

PETSc.LibPETSc.KSPSetType — Method

KSPSetType(petsclib::PetscLibType,ksp::PetscKSP, type::KSPType)

Sets the algorithm/method to be used to solve the linear system with the given KSP

Logically Collective

Input Parameters:

ksp - the Krylov space context
type - a known method

Options Database Key:

-ksp_type <method> - Sets the method; see KSPGType or use -help for a list of available methods (for instance, cg or gmres)

Level: intermediate

-seealso: , PCSetType(), KSPType, KSPRegister(), KSPCreate(), KSP

External Links

PETSc Manual: KSP/KSPSetType

source

PETSc.LibPETSc.KSPSetUp — Method

KSPSetUp(petsclib::PetscLibType,ksp::PetscKSP)

Sets up the internal data structures for the later use KSPSolve() the KSP linear iterative solver.

Collective

Input Parameter:

ksp - iterative solver, KSP, obtained from KSPCreate()

Level: developer

-seealso: , KSPCreate(), KSPSolve(), KSPDestroy(), KSP, KSPSetUpOnBlocks()

External Links

PETSc Manual: KSP/KSPSetUp

source

PETSc.LibPETSc.KSPSetUpOnBlocks — Method

KSPSetUpOnBlocks(petsclib::PetscLibType,ksp::PetscKSP)

Sets up the preconditioner for each block in the block Jacobi PCJACOBI, overlapping Schwarz PCASM, and fieldsplit PCFIELDSPLIT preconditioners

Collective

Input Parameter:

ksp - the KSP context

Level: advanced

-seealso: , PCSetUpOnBlocks(), KSPSetUp(), PCSetUp(), KSP

External Links

PETSc Manual: KSP/KSPSetUpOnBlocks

source

PETSc.LibPETSc.KSPSetUseExplicitTranspose — Method

flg::PetscBool = KSPSetUseExplicitTranspose(petsclib::PetscLibType,ksp::PetscKSP)

Determines the explicit transpose of the operator is formed in KSPSolveTranspose(). In some configurations (like GPUs) it may be explicitly formed since the solve is much more efficient.

Logically Collective

Input Parameter:

ksp - the KSP context

Output Parameter:

flg - PETSC_TRUE to transpose the system in KSPSolveTranspose(), PETSC_FALSE to not transpose (default)

Level: advanced

-seealso: , KSPSolveTranspose(), KSP

External Links

PETSc Manual: KSP/KSPSetUseExplicitTranspose

source

PETSc.LibPETSc.KSPSetUseFischerGuess — Method

KSPSetUseFischerGuess(petsclib::PetscLibType,ksp::PetscKSP, model::PetscInt, size::PetscInt)

Use the Paul Fischer algorithm or its variants to compute initial guesses for a set of solves with related right

Logically Collective

Input Parameters:

ksp - the Krylov context
model - use model 1, model 2, model 3, or any other number to turn it off
size - size of subspace used to generate initial guess

Options Database Key:

-ksp_fischer_guess <model,size> - uses the Fischer initial guess generator for repeated linear solves

Level: advanced

-seealso: , KSP, KSPSetOptionsPrefix(), KSPAppendOptionsPrefix(), KSPSetGuess(), KSPGetGuess(), KSPGuess

External Links

PETSc Manual: KSP/KSPSetUseFischerGuess

source

PETSc.LibPETSc.KSPSetWorkVecs — Method

KSPSetWorkVecs(petsclib::PetscLibType,ksp::PetscKSP, nw::PetscInt)

Sets a number of work vectors into a KSP object

Collective

Input Parameters:

ksp - iterative context
nw - number of work vectors to allocate

Level: developer

-seealso: , KSP, KSPCreateVecs()

External Links

PETSc Manual: KSP/KSPSetWorkVecs

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PETSc.LibPETSc.KSPSolve — Method

KSPSolve(petsclib::PetscLibType,ksp::PetscKSP, b::PetscVec, x::PetscVec)

Solves a linear system associated with KSP object

Collective

Input Parameters:

ksp - iterative solver obtained from KSPCreate()
b - the right-hand side vector
x - the solution (this may be the same vector as b, then b will be overwritten with the answer)

Options Database Keys:

-ksp_view_eigenvalues - compute preconditioned operators eigenvalues
-ksp_view_eigenvalues_explicit - compute the eigenvalues by forming the dense operator and using LAPACK
-ksp_view_mat binary - save matrix to the default binary viewer
-ksp_view_pmat binary - save matrix used to build preconditioner to the default binary viewer
-ksp_view_rhs binary - save right-hand side vector to the default binary viewer
-ksp_view_solution binary - save computed solution vector to the default binary viewer

(can be read later with src/ksp/tutorials/ex10.c for testing solvers)

-ksp_view_mat_explicit - for matrix-free operators, computes the matrix entries and views them
-ksp_view_preconditioned_operator_explicit - computes the product of the preconditioner and matrix as an explicit matrix and views it
-ksp_converged_reason - print reason for converged or diverged, also prints number of iterations
-ksp_view_final_residual - print 2-norm of true linear system residual at the end of the solution process
-ksp_error_if_not_converged - stop the program as soon as an error is detected in a KSPSolve()
-ksp_view_pre - print the ksp data structure before the system solution
-ksp_view - print the ksp data structure at the end of the system solution

Level: beginner

-seealso: , KSPCreate(), KSPSetUp(), KSPDestroy(), KSPSetTolerances(), KSPConvergedDefault(), KSPSolveTranspose(), KSPGetIterationNumber(), MatNullSpaceCreate(), MatSetNullSpace(), MatSetTransposeNullSpace(), KSP, KSPConvergedReasonView(), KSPCheckSolve(), KSPSetErrorIfNotConverged()

External Links

PETSc Manual: KSP/KSPSolve

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PETSc.LibPETSc.KSPSolveTranspose — Method

KSPSolveTranspose(petsclib::PetscLibType,ksp::PetscKSP, b::PetscVec, x::PetscVec)

Solves a linear system with the transpose of the matrix associated with the KSP object, A^T x = b.

Collective

Input Parameters:

ksp - iterative solver obtained from KSPCreate()
b - right-hand side vector
x - solution vector

Level: developer

-seealso: , KSPCreate(), KSPSetUp(), KSPDestroy(), KSPSetTolerances(), KSPConvergedDefault(), KSPSolve(), KSP, KSPSetOperators()

External Links

PETSc Manual: KSP/KSPSolveTranspose

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PETSc.LibPETSc.KSPUnwindPreconditioner — Method

KSPUnwindPreconditioner(petsclib::PetscLibType,ksp::PetscKSP, vsoln::PetscVec, vt1::PetscVec)

Unwinds the preconditioning in the solution. That is, takes solution to the preconditioned problem and gets the solution to the original problem from it.

Collective

Input Parameters:

ksp - iterative context
vsoln - solution vector
vt1 - temporary work vector

Output Parameter:

vsoln - contains solution on output

Level: advanced

-seealso: , KSP, KSPSetPCSide()

External Links

PETSc Manual: KSP/KSPUnwindPreconditioner

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PETSc.LibPETSc.KSPView — Method

KSPView(petsclib::PetscLibType,ksp::PetscKSP, viewer::PetscViewer)

Prints the various parameters currently set in the KSP object. For example, the convergence tolerances and KSPType. Also views the PC and Mat contained by the KSP with PCView() and MatView().

Collective

Input Parameters:

ksp - the Krylov space context
viewer - visualization context

Options Database Key:

-ksp_view - print the KSP data structure at the end of each KSPSolve() call

Level: beginner

-seealso: , KSP, PetscViewer, PCView(), PetscViewerASCIIOpen(), KSPViewFromOptions()

External Links

PETSc Manual: KSP/KSPView

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PETSc.LibPETSc.KSPViewFromOptions — Method

KSPViewFromOptions(petsclib::PetscLibType,A::PetscKSP, obj::PetscObject, name::String)

View (print) a KSP object based on values in the options database. Also views the PC and Mat contained by the KSP with PCView() and MatView().

Collective

Input Parameters:

A - Krylov solver context
obj - Optional object that provides the options prefix used to query the options database
name - command line option

Level: intermediate

-seealso: , KSP, KSPView(), PetscObjectViewFromOptions(), KSPCreate()

External Links

PETSc Manual: KSP/KSPViewFromOptions

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PETSc.LibPETSc.KSPGuessCreate — Method

guess::KSPGuess = KSPGuessCreate(petsclib::PetscLibType,comm::MPI_Comm)

Creates a KSPGuess context.

Collective

Input Parameter:

comm - MPI communicator

Output Parameter:

guess - location to put the KSPGuess context

Options Database Keys:

-ksp_guess_type <method> - Turns on generation of initial guesses and sets the method; use -help for a list of available methods
-ksp_guess_view <viewer> - view the KSPGuess object
-ksp_guess_fischer_model <a,b> - set details for the Fischer models
-ksp_guess_fischer_monitor - monitor the fischer models
-ksp_guess_fischer_tol <tol> - set the tolerance for the Fischer models
-ksp_guess_pod_size <size> - Number of snapshots
-ksp_guess_pod_monitor true - monitor the pod initial guess processing
-ksp_guess_pod_tol <tol> - Tolerance to retain eigenvectors
-ksp_guess_pod_Ainner true - Use the operator as inner product (must be SPD)

Level: developer

-seealso: , KSPSolve(), KSPGuessDestroy(), KSPGuess, KSPGuessType, KSP

External Links

PETSc Manual: Ksp/KSPGuessCreate

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PETSc.LibPETSc.KSPGuessDestroy — Method

KSPGuessDestroy(petsclib::PetscLibType,guess::KSPGuess)

Destroys KSPGuess context.

Collective

Input Parameter:

guess - initial guess object

Level: developer

-seealso: , KSPGuessCreate(), KSPGuess, KSPGuessType

External Links

PETSc Manual: Ksp/KSPGuessDestroy

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PETSc.LibPETSc.KSPGuessFischerSetModel — Method

KSPGuessFischerSetModel(petsclib::PetscLibType,guess::KSPGuess, model::PetscInt, size::PetscInt)

Set the Paul Fischer algorithm or its variants to compute the initial guess for a KSPSolve()

Logically Collective

Input Parameters:

guess - the initial guess context
model - use model 1, model 2, model 3, or any other number to turn it off
size - size of subspace used to generate initial guess

Options Database Key:

-ksp_guess_fischer_model <model,size> - uses the Fischer initial guess generator for repeated linear solves

Level: advanced

-seealso: , KSPGuess, KSPGuessCreate(), KSPSetUseFischerGuess(), KSPSetGuess(), KSPGetGuess(), KSP

External Links

PETSc Manual: Ksp/KSPGuessFischerSetModel

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PETSc.LibPETSc.KSPGuessFormGuess — Method

KSPGuessFormGuess(petsclib::PetscLibType,guess::KSPGuess, rhs::PetscVec, sol::PetscVec)

Form the initial guess

Collective

Input Parameters:

guess - the initial guess context
rhs - the current right-hand side vector
sol - the initial guess vector

Level: developer

-seealso: , KSPGuessCreate(), KSPGuess

External Links

PETSc Manual: Ksp/KSPGuessFormGuess

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PETSc.LibPETSc.KSPGuessGetType — Method

type::KSPGuessType = KSPGuessGetType(petsclib::PetscLibType,guess::KSPGuess)

Gets the KSPGuessType as a string from the KSPGuess object.

Not Collective

Input Parameter:

guess - the initial guess context

Output Parameter:

type - type of KSPGuess method

Level: developer

-seealso: , KSPGuess, KSPGuessSetType()

External Links

PETSc Manual: Ksp/KSPGuessGetType

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PETSc.LibPETSc.KSPGuessRegister — Method

KSPGuessRegister(petsclib::PetscLibType,sname::String, fnc::external)

Registers a method for initial guess computation in Krylov subspace solver package.

Not Collective, No Fortran Support

Input Parameters:

sname - name of a new user-defined solver
function - routine to create method context

-seealso: , KSPGuess, KSPGuessRegisterAll()

External Links

PETSc Manual: Ksp/KSPGuessRegister

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PETSc.LibPETSc.KSPGuessSetFromOptions — Method

KSPGuessSetFromOptions(petsclib::PetscLibType,guess::KSPGuess)

Sets the options for a KSPGuess from the options database

Collective

Input Parameter:

guess - KSPGuess object

Options Database Keys:

-ksp_guess_type <method> - Turns on generation of initial guesses and sets the method; use -help for a list of available methods
-ksp_guess_view <viewer> - view the KSPGuess object
-ksp_guess_fischer_model <a,b> - set details for the Fischer models
-ksp_guess_fischer_monitor - monitor the Fischer models
-ksp_guess_fischer_tol <tol> - set the tolerance for the Fischer models
-ksp_guess_pod_size <size> - Number of snapshots
-ksp_guess_pod_monitor true - monitor the pod initial guess processing
-ksp_guess_pod_tol <tol> - Tolerance to retain eigenvectors
-ksp_guess_pod_Ainner true - Use the operator as inner product (must be SPD)

Level: developer

-seealso: , KSPGuess, KSPGetGuess(), KSPGuessSetType(), KSPGuessType

External Links

PETSc Manual: Ksp/KSPGuessSetFromOptions

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PETSc.LibPETSc.KSPGuessSetTolerance — Method

KSPGuessSetTolerance(petsclib::PetscLibType,guess::KSPGuess, tol::PetscReal)

Sets the relative tolerance used in either eigenvalue (POD) or singular value (Fischer type 3) calculations.

Collective

Input Parameters:

guess - KSPGuess object
tol - the tolerance

Options Database Key:

-ksp_guess_fischer_tol <tol> - set the tolerance for the Fischer models
-ksp_guess_pod_tol <tol> - set the tolerance for the Pod models

Level: developer

-seealso: , KSPGuess, KSPGuessType, KSPGuessSetFromOptions()

External Links

PETSc Manual: Ksp/KSPGuessSetTolerance

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PETSc.LibPETSc.KSPGuessSetType — Method

KSPGuessSetType(petsclib::PetscLibType,guess::KSPGuess, type::KSPGuessType)

Sets the type of a KSPGuess. Each KSPGuessType provides a different algorithm for computing the initial guess.

Logically Collective

Input Parameters:

guess - the initial guess object for the Krylov method
type - a known KSPGuessType

Options Database Key:

-ksp_guess_type <method> - Turns on generation of initial guesses and sets the method; see KSPGuessType for a list of available types

Level: developer

-seealso: , KSP, KSPGuess, KSPGuessType, KSPGuessRegister(), KSPGuessCreate(), KSPGUESSFISCHER, KSPGUESSPOD

External Links

PETSc Manual: Ksp/KSPGuessSetType

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PETSc.LibPETSc.KSPGuessSetUp — Method

KSPGuessSetUp(petsclib::PetscLibType,guess::KSPGuess)

Setup the initial guess object

Collective

Input Parameter:

guess - the initial guess context

Level: developer

-seealso: , KSPGuessCreate(), KSPGuess

External Links

PETSc Manual: Ksp/KSPGuessSetUp

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PETSc.LibPETSc.KSPGuessUpdate — Method

KSPGuessUpdate(petsclib::PetscLibType,guess::KSPGuess, rhs::PetscVec, sol::PetscVec)

Updates the guess object with the current solution and rhs vector

Collective

Input Parameters:

guess - the initial guess context
rhs - the corresponding rhs
sol - the computed solution

Level: developer

-seealso: , KSPGuessCreate(), KSPGuess

External Links

PETSc Manual: Ksp/KSPGuessUpdate

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PETSc.LibPETSc.KSPGuessView — Method

KSPGuessView(petsclib::PetscLibType,guess::KSPGuess, view::PetscViewer)

View the KSPGuess object

Logically Collective

Input Parameters:

guess - the initial guess object for the Krylov method
view - the viewer object

Options Database Key:

-ksp_guess_view viewer - view the KSPGuess object

Level: developer

-seealso: , KSP, KSPGuess, KSPGuessType, KSPGuessRegister(), KSPGuessCreate(), PetscViewer

External Links

PETSc Manual: Ksp/KSPGuessView

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