xref: /petsc/include/petscksp.h (revision 5a1c817a1ff20b06b5c0523d36cb16135db0c77b)

/*
   Defines the interface functions for the Krylov subspace accelerators.
*/
#ifndef __PETSCKSP_H
#define __PETSCKSP_H
#include <petscpc.h>

PETSC_EXTERN PetscErrorCode KSPInitializePackage(void);

/*S
     KSP - Abstract PETSc object that manages all Krylov methods. This is the object that manages the
         linear solves in PETSc (even those such as direct solvers that do no use Krylov accelerators).

   Level: beginner

  Concepts: Krylov methods

        Notes: When a direct solver is used but no Krylov solver is used the KSP object is still used by with a
       KSPType of KSPPREONLY (meaning application of the preconditioner is only used as the linear solver).

.seealso:  KSPCreate(), KSPSetType(), KSPType, SNES, TS, PC, KSP, KSPDestroy()
S*/
typedef struct _p_KSP*     KSP;

/*J
    KSPType - String with the name of a PETSc Krylov method.

   Level: beginner

.seealso: KSPSetType(), KSP, KSPRegister(), KSPCreate(), KSPSetFromOptions()
J*/
typedef const char* KSPType;
#define KSPRICHARDSON "richardson"
#define KSPCHEBYSHEV  "chebyshev"
#define KSPCG         "cg"
#define KSPGROPPCG    "groppcg"
#define KSPPIPECG     "pipecg"
#define   KSPCGNE       "cgne"
#define   KSPNASH       "nash"
#define   KSPSTCG       "stcg"
#define   KSPGLTR       "gltr"
#define KSPGMRES      "gmres"
#define   KSPFGMRES     "fgmres"
#define   KSPLGMRES     "lgmres"
#define   KSPDGMRES     "dgmres"
#define   KSPPGMRES     "pgmres"
#define KSPTCQMR      "tcqmr"
#define KSPBCGS       "bcgs"
#define   KSPIBCGS      "ibcgs"
#define   KSPFBCGS      "fbcgs"
#define   KSPFBCGSR     "fbcgsr"
#define   KSPBCGSL      "bcgsl"
#define KSPCGS        "cgs"
#define KSPTFQMR      "tfqmr"
#define KSPCR         "cr"
#define KSPPIPECR     "pipecr"
#define KSPLSQR       "lsqr"
#define KSPPREONLY    "preonly"
#define KSPQCG        "qcg"
#define KSPBICG       "bicg"
#define KSPMINRES     "minres"
#define KSPSYMMLQ     "symmlq"
#define KSPLCD        "lcd"
#define KSPPYTHON     "python"
#define KSPGCR        "gcr"
#define KSPSPECEST    "specest"

/* Logging support */
PETSC_EXTERN PetscClassId KSP_CLASSID;
PETSC_EXTERN PetscClassId DMKSP_CLASSID;

PETSC_EXTERN PetscErrorCode KSPCreate(MPI_Comm,KSP *);
PETSC_EXTERN PetscErrorCode KSPSetType(KSP,KSPType);
PETSC_EXTERN PetscErrorCode KSPSetUp(KSP);
PETSC_EXTERN PetscErrorCode KSPSetUpOnBlocks(KSP);
PETSC_EXTERN PetscErrorCode KSPSolve(KSP,Vec,Vec);
PETSC_EXTERN PetscErrorCode KSPSolveTranspose(KSP,Vec,Vec);
PETSC_EXTERN PetscErrorCode KSPReset(KSP);
PETSC_EXTERN PetscErrorCode KSPDestroy(KSP*);

PETSC_EXTERN PetscFunctionList KSPList;
PETSC_EXTERN PetscBool         KSPRegisterAllCalled;
PETSC_EXTERN PetscErrorCode KSPRegisterAll(void);
PETSC_EXTERN PetscErrorCode KSPRegister(const char[],PetscErrorCode (*)(KSP));
PETSC_EXTERN PetscErrorCode KSPMatRegisterAll(void);

PETSC_EXTERN PetscErrorCode KSPGetType(KSP,KSPType *);
PETSC_EXTERN PetscErrorCode KSPSetPCSide(KSP,PCSide);
PETSC_EXTERN PetscErrorCode KSPGetPCSide(KSP,PCSide*);
PETSC_EXTERN PetscErrorCode KSPGetTolerances(KSP,PetscReal*,PetscReal*,PetscReal*,PetscInt*);
PETSC_EXTERN PetscErrorCode KSPSetTolerances(KSP,PetscReal,PetscReal,PetscReal,PetscInt);
PETSC_EXTERN PetscErrorCode KSPSetInitialGuessNonzero(KSP,PetscBool );
PETSC_EXTERN PetscErrorCode KSPGetInitialGuessNonzero(KSP,PetscBool  *);
PETSC_EXTERN PetscErrorCode KSPSetInitialGuessKnoll(KSP,PetscBool );
PETSC_EXTERN PetscErrorCode KSPGetInitialGuessKnoll(KSP,PetscBool *);
PETSC_EXTERN PetscErrorCode KSPSetErrorIfNotConverged(KSP,PetscBool );
PETSC_EXTERN PetscErrorCode KSPGetErrorIfNotConverged(KSP,PetscBool  *);
PETSC_EXTERN PetscErrorCode KSPGetComputeEigenvalues(KSP,PetscBool *);
PETSC_EXTERN PetscErrorCode KSPSetComputeEigenvalues(KSP,PetscBool );
PETSC_EXTERN PetscErrorCode KSPGetComputeSingularValues(KSP,PetscBool *);
PETSC_EXTERN PetscErrorCode KSPSetComputeSingularValues(KSP,PetscBool );
PETSC_EXTERN PetscErrorCode KSPGetRhs(KSP,Vec *);
PETSC_EXTERN PetscErrorCode KSPGetSolution(KSP,Vec *);
PETSC_EXTERN PetscErrorCode KSPGetResidualNorm(KSP,PetscReal*);
PETSC_EXTERN PetscErrorCode KSPGetIterationNumber(KSP,PetscInt*);
PETSC_EXTERN PetscErrorCode KSPSetNullSpace(KSP,MatNullSpace);
PETSC_EXTERN PetscErrorCode KSPGetNullSpace(KSP,MatNullSpace*);
PETSC_EXTERN PetscErrorCode KSPGetVecs(KSP,PetscInt,Vec**,PetscInt,Vec**);

PETSC_EXTERN PetscErrorCode KSPSetPreSolve(KSP,PetscErrorCode (*)(KSP,Vec,Vec,void*),void*);
PETSC_EXTERN PetscErrorCode KSPSetPostSolve(KSP,PetscErrorCode (*)(KSP,Vec,Vec,void*),void*);

PETSC_EXTERN PetscErrorCode KSPSetPC(KSP,PC);
PETSC_EXTERN PetscErrorCode KSPGetPC(KSP,PC*);

PETSC_EXTERN PetscErrorCode KSPMonitor(KSP,PetscInt,PetscReal);
PETSC_EXTERN PetscErrorCode KSPMonitorSet(KSP,PetscErrorCode (*)(KSP,PetscInt,PetscReal,void*),void *,PetscErrorCode (*)(void**));
PETSC_EXTERN PetscErrorCode KSPMonitorCancel(KSP);
PETSC_EXTERN PetscErrorCode KSPGetMonitorContext(KSP,void **);
PETSC_EXTERN PetscErrorCode KSPGetResidualHistory(KSP,PetscReal*[],PetscInt *);
PETSC_EXTERN PetscErrorCode KSPSetResidualHistory(KSP,PetscReal[],PetscInt,PetscBool );

PETSC_EXTERN PetscErrorCode KSPBuildSolutionDefault(KSP,Vec,Vec*);
PETSC_EXTERN PetscErrorCode KSPBuildResidualDefault(KSP,Vec,Vec,Vec *);
PETSC_EXTERN PetscErrorCode KSPDestroyDefault(KSP);
PETSC_EXTERN PetscErrorCode KSPSetWorkVecs(KSP,PetscInt);

PETSC_EXTERN PetscErrorCode PCKSPGetKSP(PC,KSP*);
PETSC_EXTERN PetscErrorCode PCBJacobiGetSubKSP(PC,PetscInt*,PetscInt*,KSP*[]);
PETSC_EXTERN PetscErrorCode PCASMGetSubKSP(PC,PetscInt*,PetscInt*,KSP*[]);
PETSC_EXTERN PetscErrorCode PCGASMGetSubKSP(PC,PetscInt*,PetscInt*,KSP*[]);
PETSC_EXTERN PetscErrorCode PCFieldSplitGetSubKSP(PC,PetscInt*,KSP*[]);
PETSC_EXTERN PetscErrorCode PCMGGetSmoother(PC,PetscInt,KSP*);
PETSC_EXTERN PetscErrorCode PCMGGetSmootherDown(PC,PetscInt,KSP*);
PETSC_EXTERN PetscErrorCode PCMGGetSmootherUp(PC,PetscInt,KSP*);
PETSC_EXTERN PetscErrorCode PCMGGetCoarseSolve(PC,KSP*);
PETSC_EXTERN PetscErrorCode PCGalerkinGetKSP(PC,KSP *);

PETSC_EXTERN PetscErrorCode KSPBuildSolution(KSP,Vec,Vec *);
PETSC_EXTERN PetscErrorCode KSPBuildResidual(KSP,Vec,Vec,Vec *);

PETSC_EXTERN PetscErrorCode KSPRichardsonSetScale(KSP,PetscReal);
PETSC_EXTERN PetscErrorCode KSPRichardsonSetSelfScale(KSP,PetscBool );
PETSC_EXTERN PetscErrorCode KSPChebyshevSetEigenvalues(KSP,PetscReal,PetscReal);
PETSC_EXTERN PetscErrorCode KSPChebyshevSetEstimateEigenvalues(KSP,PetscReal,PetscReal,PetscReal,PetscReal);
PETSC_EXTERN PetscErrorCode KSPChebyshevEstEigSetRandom(KSP,PetscRandom);
PETSC_EXTERN PetscErrorCode KSPChebyshevSetNewMatrix(KSP);
PETSC_EXTERN PetscErrorCode KSPComputeExtremeSingularValues(KSP,PetscReal*,PetscReal*);
PETSC_EXTERN PetscErrorCode KSPComputeEigenvalues(KSP,PetscInt,PetscReal*,PetscReal*,PetscInt *);
PETSC_EXTERN PetscErrorCode KSPComputeEigenvaluesExplicitly(KSP,PetscInt,PetscReal*,PetscReal*);

PETSC_EXTERN PetscErrorCode KSPGMRESSetRestart(KSP, PetscInt);
PETSC_EXTERN PetscErrorCode KSPGMRESGetRestart(KSP, PetscInt*);
PETSC_EXTERN PetscErrorCode KSPGMRESSetHapTol(KSP,PetscReal);

PETSC_EXTERN PetscErrorCode KSPGMRESSetPreAllocateVectors(KSP);
PETSC_EXTERN PetscErrorCode KSPGMRESSetOrthogonalization(KSP,PetscErrorCode (*)(KSP,PetscInt));
PETSC_EXTERN PetscErrorCode KSPGMRESGetOrthogonalization(KSP,PetscErrorCode (**)(KSP,PetscInt));
PETSC_EXTERN PetscErrorCode KSPGMRESModifiedGramSchmidtOrthogonalization(KSP,PetscInt);
PETSC_EXTERN PetscErrorCode KSPGMRESClassicalGramSchmidtOrthogonalization(KSP,PetscInt);

PETSC_EXTERN PetscErrorCode KSPLGMRESSetAugDim(KSP,PetscInt);
PETSC_EXTERN PetscErrorCode KSPLGMRESSetConstant(KSP);

PETSC_EXTERN PetscErrorCode KSPGCRSetRestart(KSP,PetscInt);
PETSC_EXTERN PetscErrorCode KSPGCRGetRestart(KSP,PetscInt*);
PETSC_EXTERN PetscErrorCode KSPGCRSetModifyPC(KSP,PetscErrorCode (*)(KSP,PetscInt,PetscReal,void*),void*,PetscErrorCode(*)(void*));

/*E
    KSPGMRESCGSRefinementType - How the classical (unmodified) Gram-Schmidt is performed.

   Level: advanced

.seealso: KSPGMRESClassicalGramSchmidtOrthogonalization(), KSPGMRESSetOrthogonalization(), KSPGMRESGetOrthogonalization(),
          KSPGMRESSetCGSRefinementType(), KSPGMRESGetCGSRefinementType(), KSPGMRESModifiedGramSchmidtOrthogonalization()

E*/
typedef enum {KSP_GMRES_CGS_REFINE_NEVER, KSP_GMRES_CGS_REFINE_IFNEEDED, KSP_GMRES_CGS_REFINE_ALWAYS} KSPGMRESCGSRefinementType;
PETSC_EXTERN const char *const KSPGMRESCGSRefinementTypes[];
/*MC
    KSP_GMRES_CGS_REFINE_NEVER - Just do the classical (unmodified) Gram-Schmidt process

   Level: advanced

   Note: Possible unstable, but the fastest to compute

.seealso: KSPGMRESClassicalGramSchmidtOrthogonalization(), KSPGMRESSetOrthogonalization(), KSPGMRESGetOrthogonalization(),
          KSPGMRESSetCGSRefinementType(), KSPGMRESGetCGSRefinementType(), KSP_GMRES_CGS_REFINE_IFNEEDED, KSP_GMRES_CGS_REFINE_ALWAYS,
          KSPGMRESModifiedGramSchmidtOrthogonalization()
M*/

/*MC
    KSP_GMRES_CGS_REFINE_IFNEEDED - Do the classical (unmodified) Gram-Schmidt process and one step of
          iterative refinement if an estimate of the orthogonality of the resulting vectors indicates
          poor orthogonality.

   Level: advanced

   Note: This is slower than KSP_GMRES_CGS_REFINE_NEVER because it requires an extra norm computation to
     estimate the orthogonality but is more stable.

.seealso: KSPGMRESClassicalGramSchmidtOrthogonalization(), KSPGMRESSetOrthogonalization(), KSPGMRESGetOrthogonalization(),
          KSPGMRESSetCGSRefinementType(), KSPGMRESGetCGSRefinementType(), KSP_GMRES_CGS_REFINE_NEVER, KSP_GMRES_CGS_REFINE_ALWAYS,
          KSPGMRESModifiedGramSchmidtOrthogonalization()
M*/

/*MC
    KSP_GMRES_CGS_REFINE_NEVER - Do two steps of the classical (unmodified) Gram-Schmidt process.

   Level: advanced

   Note: This is roughly twice the cost of KSP_GMRES_CGS_REFINE_NEVER because it performs the process twice
     but it saves the extra norm calculation needed by KSP_GMRES_CGS_REFINE_IFNEEDED.

        You should only use this if you absolutely know that the iterative refinement is needed.

.seealso: KSPGMRESClassicalGramSchmidtOrthogonalization(), KSPGMRESSetOrthogonalization(), KSPGMRESGetOrthogonalization(),
          KSPGMRESSetCGSRefinementType(), KSPGMRESGetCGSRefinementType(), KSP_GMRES_CGS_REFINE_IFNEEDED, KSP_GMRES_CGS_REFINE_ALWAYS,
          KSPGMRESModifiedGramSchmidtOrthogonalization()
M*/

PETSC_EXTERN PetscErrorCode KSPGMRESSetCGSRefinementType(KSP,KSPGMRESCGSRefinementType);
PETSC_EXTERN PetscErrorCode KSPGMRESGetCGSRefinementType(KSP,KSPGMRESCGSRefinementType*);

PETSC_EXTERN PetscErrorCode KSPFGMRESModifyPCNoChange(KSP,PetscInt,PetscInt,PetscReal,void*);
PETSC_EXTERN PetscErrorCode KSPFGMRESModifyPCKSP(KSP,PetscInt,PetscInt,PetscReal,void*);
PETSC_EXTERN PetscErrorCode KSPFGMRESSetModifyPC(KSP,PetscErrorCode (*)(KSP,PetscInt,PetscInt,PetscReal,void*),void*,PetscErrorCode(*)(void*));

PETSC_EXTERN PetscErrorCode KSPQCGSetTrustRegionRadius(KSP,PetscReal);
PETSC_EXTERN PetscErrorCode KSPQCGGetQuadratic(KSP,PetscReal*);
PETSC_EXTERN PetscErrorCode KSPQCGGetTrialStepNorm(KSP,PetscReal*);

PETSC_EXTERN PetscErrorCode KSPBCGSLSetXRes(KSP,PetscReal);
PETSC_EXTERN PetscErrorCode KSPBCGSLSetPol(KSP,PetscBool );
PETSC_EXTERN PetscErrorCode KSPBCGSLSetEll(KSP,PetscInt);
PETSC_EXTERN PetscErrorCode KSPBCGSLSetUsePseudoinverse(KSP,PetscBool);

PETSC_EXTERN PetscErrorCode KSPSetFromOptions(KSP);
PETSC_EXTERN PetscErrorCode KSPAddOptionsChecker(PetscErrorCode (*)(KSP));

PETSC_EXTERN PetscErrorCode KSPMonitorSingularValue(KSP,PetscInt,PetscReal,void *);
PETSC_EXTERN PetscErrorCode KSPMonitorDefault(KSP,PetscInt,PetscReal,void *);
PETSC_EXTERN PetscErrorCode KSPLSQRMonitorDefault(KSP,PetscInt,PetscReal,void *);
PETSC_EXTERN PetscErrorCode KSPMonitorRange(KSP,PetscInt,PetscReal,void *);
PETSC_EXTERN PetscErrorCode KSPMonitorDynamicTolerance(KSP ksp,PetscInt its,PetscReal fnorm,void *dummy);
PETSC_EXTERN PetscErrorCode KSPMonitorDynamicToleranceDestroy(void **dummy);
PETSC_EXTERN PetscErrorCode KSPMonitorTrueResidualNorm(KSP,PetscInt,PetscReal,void *);
PETSC_EXTERN PetscErrorCode KSPMonitorTrueResidualMaxNorm(KSP,PetscInt,PetscReal,void *);
PETSC_EXTERN PetscErrorCode KSPMonitorDefaultShort(KSP,PetscInt,PetscReal,void *);
PETSC_EXTERN PetscErrorCode KSPMonitorSolution(KSP,PetscInt,PetscReal,void *);
PETSC_EXTERN PetscErrorCode KSPMonitorSAWs(KSP,PetscInt,PetscReal,void*);
PETSC_EXTERN PetscErrorCode KSPMonitorSAWsCreate(KSP,void**);
PETSC_EXTERN PetscErrorCode KSPMonitorSAWsDestroy(void**);
PETSC_EXTERN PetscErrorCode KSPGMRESMonitorKrylov(KSP,PetscInt,PetscReal,void *);

PETSC_EXTERN PetscErrorCode KSPUnwindPreconditioner(KSP,Vec,Vec);
PETSC_EXTERN PetscErrorCode KSPInitialResidual(KSP,Vec,Vec,Vec,Vec,Vec);

PETSC_EXTERN PetscErrorCode KSPSetOperators(KSP,Mat,Mat,MatStructure);
PETSC_EXTERN PetscErrorCode KSPGetOperators(KSP,Mat*,Mat*,MatStructure*);
PETSC_EXTERN PetscErrorCode KSPGetOperatorsSet(KSP,PetscBool *,PetscBool *);
PETSC_EXTERN PetscErrorCode KSPSetOptionsPrefix(KSP,const char[]);
PETSC_EXTERN PetscErrorCode KSPAppendOptionsPrefix(KSP,const char[]);
PETSC_EXTERN PetscErrorCode KSPGetOptionsPrefix(KSP,const char*[]);
PETSC_EXTERN PetscErrorCode KSPSetTabLevel(KSP,PetscInt);
PETSC_EXTERN PetscErrorCode KSPGetTabLevel(KSP,PetscInt*);

PETSC_EXTERN PetscErrorCode KSPSetDiagonalScale(KSP,PetscBool );
PETSC_EXTERN PetscErrorCode KSPGetDiagonalScale(KSP,PetscBool *);
PETSC_EXTERN PetscErrorCode KSPSetDiagonalScaleFix(KSP,PetscBool );
PETSC_EXTERN PetscErrorCode KSPGetDiagonalScaleFix(KSP,PetscBool *);

PETSC_EXTERN PetscErrorCode KSPView(KSP,PetscViewer);
PETSC_EXTERN PetscErrorCode KSPLoad(KSP,PetscViewer);
PETSC_STATIC_INLINE PetscErrorCode KSPViewFromOptions(KSP A,const char prefix[],const char name[]) {return PetscObjectViewFromOptions((PetscObject)A,prefix,name);}

#define KSP_FILE_CLASSID 1211223

PETSC_EXTERN PetscErrorCode KSPLSQRSetStandardErrorVec(KSP,Vec);
PETSC_EXTERN PetscErrorCode KSPLSQRGetStandardErrorVec(KSP,Vec*);

PETSC_EXTERN PetscErrorCode PCRedundantGetKSP(PC,KSP*);
PETSC_EXTERN PetscErrorCode PCRedistributeGetKSP(PC,KSP*);

/*E
    KSPNormType - Norm that is passed in the Krylov convergence
       test routines.

   Level: advanced

   Each solver only supports a subset of these and some may support different ones
   depending on left or right preconditioning, see KSPSetPCSide()

   Notes: this must match finclude/petscksp.h

.seealso: KSPSolve(), KSPGetConvergedReason(), KSPSetNormType(),
          KSPSetConvergenceTest(), KSPSetPCSide()
E*/
typedef enum {KSP_NORM_DEFAULT = -1,KSP_NORM_NONE = 0,KSP_NORM_PRECONDITIONED = 1,KSP_NORM_UNPRECONDITIONED = 2,KSP_NORM_NATURAL = 3} KSPNormType;
#define KSP_NORM_MAX (KSP_NORM_NATURAL + 1)
PETSC_EXTERN const char *const*const KSPNormTypes;

/*MC
    KSP_NORM_NONE - Do not compute a norm during the Krylov process. This will
          possibly save some computation but means the convergence test cannot
          be based on a norm of a residual etc.

   Level: advanced

    Note: Some Krylov methods need to compute a residual norm and then this option is ignored

.seealso: KSPNormType, KSPSetNormType(), KSP_NORM_PRECONDITIONED, KSP_NORM_UNPRECONDITIONED, KSP_NORM_NATURAL
M*/

/*MC
    KSP_NORM_PRECONDITIONED - Compute the norm of the preconditioned residual and pass that to the
       convergence test routine.

   Level: advanced

.seealso: KSPNormType, KSPSetNormType(), KSP_NORM_NONE, KSP_NORM_UNPRECONDITIONED, KSP_NORM_NATURAL, KSPSetConvergenceTest()
M*/

/*MC
    KSP_NORM_UNPRECONDITIONED - Compute the norm of the true residual (b - A*x) and pass that to the
       convergence test routine.

   Level: advanced

.seealso: KSPNormType, KSPSetNormType(), KSP_NORM_NONE, KSP_NORM_PRECONDITIONED, KSP_NORM_NATURAL, KSPSetConvergenceTest()
M*/

/*MC
    KSP_NORM_NATURAL - Compute the 'natural norm' of residual sqrt((b - A*x)*B*(b - A*x)) and pass that to the
       convergence test routine. This is only supported by  KSPCG, KSPCR, KSPCGNE, KSPCGS

   Level: advanced

.seealso: KSPNormType, KSPSetNormType(), KSP_NORM_NONE, KSP_NORM_PRECONDITIONED, KSP_NORM_UNPRECONDITIONED, KSPSetConvergenceTest()
M*/

PETSC_EXTERN PetscErrorCode KSPSetNormType(KSP,KSPNormType);
PETSC_EXTERN PetscErrorCode KSPGetNormType(KSP,KSPNormType*);
PETSC_EXTERN PetscErrorCode KSPSetSupportedNorm(KSP ksp,KSPNormType,PCSide,PetscInt);
PETSC_EXTERN PetscErrorCode KSPSetCheckNormIteration(KSP,PetscInt);
PETSC_EXTERN PetscErrorCode KSPSetLagNorm(KSP,PetscBool);

/*E
    KSPConvergedReason - reason a Krylov method was said to
         have converged or diverged

   Level: beginner

   Notes: See KSPGetConvergedReason() for explanation of each value

   Developer notes: this must match finclude/petscksp.h

      The string versions of these are KSPConvergedReasons; if you change
      any of the values here also change them that array of names.

.seealso: KSPSolve(), KSPGetConvergedReason(), KSPSetTolerances()
E*/
typedef enum {/* converged */
              KSP_CONVERGED_RTOL_NORMAL        =  1,
              KSP_CONVERGED_ATOL_NORMAL        =  9,
              KSP_CONVERGED_RTOL               =  2,
              KSP_CONVERGED_ATOL               =  3,
              KSP_CONVERGED_ITS                =  4,
              KSP_CONVERGED_CG_NEG_CURVE       =  5,
              KSP_CONVERGED_CG_CONSTRAINED     =  6,
              KSP_CONVERGED_STEP_LENGTH        =  7,
              KSP_CONVERGED_HAPPY_BREAKDOWN    =  8,
              /* diverged */
              KSP_DIVERGED_NULL                = -2,
              KSP_DIVERGED_ITS                 = -3,
              KSP_DIVERGED_DTOL                = -4,
              KSP_DIVERGED_BREAKDOWN           = -5,
              KSP_DIVERGED_BREAKDOWN_BICG      = -6,
              KSP_DIVERGED_NONSYMMETRIC        = -7,
              KSP_DIVERGED_INDEFINITE_PC       = -8,
              KSP_DIVERGED_NANORINF            = -9,
              KSP_DIVERGED_INDEFINITE_MAT      = -10,

              KSP_CONVERGED_ITERATING          =  0} KSPConvergedReason;
PETSC_EXTERN const char *const*KSPConvergedReasons;

/*MC
     KSP_CONVERGED_RTOL - norm(r) <= rtol*norm(b)

   Level: beginner

   See KSPNormType and KSPSetNormType() for possible norms that may be used. By default
       for left preconditioning it is the 2-norm of the preconditioned residual, and the
       2-norm of the residual for right preconditioning

.seealso:  KSPSolve(), KSPGetConvergedReason(), KSPConvergedReason, KSPSetTolerances()

M*/

/*MC
     KSP_CONVERGED_ATOL - norm(r) <= atol

   Level: beginner

   See KSPNormType and KSPSetNormType() for possible norms that may be used. By default
       for left preconditioning it is the 2-norm of the preconditioned residual, and the
       2-norm of the residual for right preconditioning

   Level: beginner

.seealso:  KSPSolve(), KSPGetConvergedReason(), KSPConvergedReason, KSPSetTolerances()

M*/

/*MC
     KSP_DIVERGED_DTOL - norm(r) >= dtol*norm(b)

   Level: beginner

   See KSPNormType and KSPSetNormType() for possible norms that may be used. By default
       for left preconditioning it is the 2-norm of the preconditioned residual, and the
       2-norm of the residual for right preconditioning

   Level: beginner

.seealso:  KSPSolve(), KSPGetConvergedReason(), KSPConvergedReason, KSPSetTolerances()

M*/

/*MC
     KSP_DIVERGED_ITS - Ran out of iterations before any convergence criteria was
      reached

   Level: beginner

.seealso:  KSPSolve(), KSPGetConvergedReason(), KSPConvergedReason, KSPSetTolerances()

M*/

/*MC
     KSP_CONVERGED_ITS - Used by the KSPPREONLY solver after the single iteration of
           the preconditioner is applied. Also used when the KSPConvergedSkip() convergence
           test routine is set in KSP.


   Level: beginner


.seealso:  KSPSolve(), KSPGetConvergedReason(), KSPConvergedReason, KSPSetTolerances()

M*/

/*MC
     KSP_DIVERGED_BREAKDOWN - A breakdown in the Krylov method was detected so the
          method could not continue to enlarge the Krylov space. Could be due to a singlular matrix or
          preconditioner.

   Level: beginner

.seealso:  KSPSolve(), KSPGetConvergedReason(), KSPConvergedReason, KSPSetTolerances()

M*/

/*MC
     KSP_DIVERGED_BREAKDOWN_BICG - A breakdown in the KSPBICG method was detected so the
          method could not continue to enlarge the Krylov space.


   Level: beginner


.seealso:  KSPSolve(), KSPGetConvergedReason(), KSPConvergedReason, KSPSetTolerances()

M*/

/*MC
     KSP_DIVERGED_NONSYMMETRIC - It appears the operator or preconditioner is not
        symmetric and this Krylov method (KSPCG, KSPMINRES, KSPCR) requires symmetry

   Level: beginner

.seealso:  KSPSolve(), KSPGetConvergedReason(), KSPConvergedReason, KSPSetTolerances()

M*/

/*MC
     KSP_DIVERGED_INDEFINITE_PC - It appears the preconditioner is indefinite (has both
        positive and negative eigenvalues) and this Krylov method (KSPCG) requires it to
        be positive definite

   Level: beginner

     Notes: This can happen with the PCICC preconditioner, use -pc_factor_shift_positive_definite to force
  the PCICC preconditioner to generate a positive definite preconditioner

.seealso:  KSPSolve(), KSPGetConvergedReason(), KSPConvergedReason, KSPSetTolerances()

M*/

/*MC
     KSP_CONVERGED_ITERATING - This flag is returned if you call KSPGetConvergedReason()
        while the KSPSolve() is still running.

   Level: beginner

.seealso:  KSPSolve(), KSPGetConvergedReason(), KSPConvergedReason, KSPSetTolerances()

M*/

PETSC_EXTERN PetscErrorCode KSPSetConvergenceTest(KSP,PetscErrorCode (*)(KSP,PetscInt,PetscReal,KSPConvergedReason*,void*),void *,PetscErrorCode (*)(void*));
PETSC_EXTERN PetscErrorCode KSPGetConvergenceContext(KSP,void **);
PETSC_EXTERN PetscErrorCode KSPConvergedDefault(KSP,PetscInt,PetscReal,KSPConvergedReason*,void *);
PETSC_EXTERN PetscErrorCode KSPConvergedLSQR(KSP,PetscInt,PetscReal,KSPConvergedReason*,void *);
PETSC_EXTERN PetscErrorCode KSPConvergedDefaultDestroy(void *);
PETSC_EXTERN PetscErrorCode KSPConvergedDefaultCreate(void **);
PETSC_EXTERN PetscErrorCode KSPConvergedDefaultSetUIRNorm(KSP);
PETSC_EXTERN PetscErrorCode KSPConvergedDefaultSetUMIRNorm(KSP);
PETSC_EXTERN PetscErrorCode KSPConvergedSkip(KSP,PetscInt,PetscReal,KSPConvergedReason*,void *);
PETSC_EXTERN PetscErrorCode KSPGetConvergedReason(KSP,KSPConvergedReason *);

PETSC_DEPRECATED("Use KSPConvergedDefault()") PETSC_STATIC_INLINE void KSPDefaultConverged(void) { /* never called */ }
#define KSPDefaultConverged (KSPDefaultConverged, KSPConvergedDefault)
PETSC_DEPRECATED("Use KSPConvergedDefaultDestroy()") PETSC_STATIC_INLINE void KSPDefaultConvergedDestroy(void) { /* never called */ }
#define KSPDefaultConvergedDestroy (KSPDefaultConvergedDestroy, KSPConvergedDefaultDestroy)
PETSC_DEPRECATED("Use KSPConvergedDefaultCreate()") PETSC_STATIC_INLINE void KSPDefaultConvergedCreate(void) { /* never called */ }
#define KSPDefaultConvergedCreate (KSPDefaultConvergedCreate, KSPConvergedDefaultCreate)
PETSC_DEPRECATED("Use KSPConvergedDefaultSetUIRNorm()") PETSC_STATIC_INLINE void KSPDefaultConvergedSetUIRNorm(void) { /* never called */ }
#define KSPDefaultConvergedSetUIRNorm (KSPDefaultConvergedSetUIRNorm, KSPConvergedDefaultSetUIRNorm)
PETSC_DEPRECATED("Use KSPConvergedDefaultSetUMIRNorm()") PETSC_STATIC_INLINE void KSPDefaultConvergedSetUMIRNorm(void) { /* never called */ }
#define KSPDefaultConvergedSetUMIRNorm (KSPDefaultConvergedSetUMIRNorm, KSPConvergedDefaultSetUMIRNorm)
PETSC_DEPRECATED("Use KSPConvergedSkip()") PETSC_STATIC_INLINE void KSPSkipConverged(void) { /* never called */ }
#define KSPSkipConverged (KSPSkipConverged, KSPConvergedSkip)

PETSC_EXTERN PetscErrorCode KSPComputeExplicitOperator(KSP,Mat *);

/*E
    KSPCGType - Determines what type of CG to use

   Level: beginner

.seealso: KSPCGSetType()
E*/
typedef enum {KSP_CG_SYMMETRIC=0,KSP_CG_HERMITIAN=1} KSPCGType;
PETSC_EXTERN const char *const KSPCGTypes[];

PETSC_EXTERN PetscErrorCode KSPCGSetType(KSP,KSPCGType);
PETSC_EXTERN PetscErrorCode KSPCGUseSingleReduction(KSP,PetscBool );

PETSC_EXTERN PetscErrorCode KSPNASHSetRadius(KSP,PetscReal);
PETSC_EXTERN PetscErrorCode KSPNASHGetNormD(KSP,PetscReal *);
PETSC_EXTERN PetscErrorCode KSPNASHGetObjFcn(KSP,PetscReal *);

PETSC_EXTERN PetscErrorCode KSPSTCGSetRadius(KSP,PetscReal);
PETSC_EXTERN PetscErrorCode KSPSTCGGetNormD(KSP,PetscReal *);
PETSC_EXTERN PetscErrorCode KSPSTCGGetObjFcn(KSP,PetscReal *);

PETSC_EXTERN PetscErrorCode KSPGLTRSetRadius(KSP,PetscReal);
PETSC_EXTERN PetscErrorCode KSPGLTRGetNormD(KSP,PetscReal *);
PETSC_EXTERN PetscErrorCode KSPGLTRGetObjFcn(KSP,PetscReal *);
PETSC_EXTERN PetscErrorCode KSPGLTRGetMinEig(KSP,PetscReal *);
PETSC_EXTERN PetscErrorCode KSPGLTRGetLambda(KSP,PetscReal *);

PETSC_EXTERN PetscErrorCode KSPPythonSetType(KSP,const char[]);

PETSC_EXTERN PetscErrorCode PCPreSolve(PC,KSP);
PETSC_EXTERN PetscErrorCode PCPostSolve(PC,KSP);

#include <petscdrawtypes.h>
PETSC_EXTERN PetscErrorCode KSPMonitorLGResidualNormCreate(const char[],const char[],int,int,int,int,PetscDrawLG*);
PETSC_EXTERN PetscErrorCode KSPMonitorLGResidualNorm(KSP,PetscInt,PetscReal,void*);
PETSC_EXTERN PetscErrorCode KSPMonitorLGResidualNormDestroy(PetscDrawLG*);
PETSC_EXTERN PetscErrorCode KSPMonitorLGTrueResidualNormCreate(MPI_Comm,const char[],const char[],int,int,int,int,PetscDrawLG*);
PETSC_EXTERN PetscErrorCode KSPMonitorLGTrueResidualNorm(KSP,PetscInt,PetscReal,void*);
PETSC_EXTERN PetscErrorCode KSPMonitorLGTrueResidualNormDestroy(PetscDrawLG*);
PETSC_EXTERN PetscErrorCode KSPMonitorLGRange(KSP,PetscInt,PetscReal,void*);

PETSC_EXTERN PetscErrorCode PCShellSetPreSolve(PC,PetscErrorCode (*)(PC,KSP,Vec,Vec));
PETSC_EXTERN PetscErrorCode PCShellSetPostSolve(PC,PetscErrorCode (*)(PC,KSP,Vec,Vec));

/* see src/ksp/ksp/interface/iguess.c */
typedef struct _p_KSPFischerGuess {PetscInt method,curl,maxl,refcnt;PetscBool  monitor;Mat mat; KSP ksp;}* KSPFischerGuess;

PETSC_EXTERN PetscErrorCode KSPFischerGuessCreate(KSP,PetscInt,PetscInt,KSPFischerGuess*);
PETSC_EXTERN PetscErrorCode KSPFischerGuessDestroy(KSPFischerGuess*);
PETSC_EXTERN PetscErrorCode KSPFischerGuessReset(KSPFischerGuess);
PETSC_EXTERN PetscErrorCode KSPFischerGuessUpdate(KSPFischerGuess,Vec);
PETSC_EXTERN PetscErrorCode KSPFischerGuessFormGuess(KSPFischerGuess,Vec,Vec);
PETSC_EXTERN PetscErrorCode KSPFischerGuessSetFromOptions(KSPFischerGuess);

PETSC_EXTERN PetscErrorCode KSPSetUseFischerGuess(KSP,PetscInt,PetscInt);
PETSC_EXTERN PetscErrorCode KSPSetFischerGuess(KSP,KSPFischerGuess);
PETSC_EXTERN PetscErrorCode KSPGetFischerGuess(KSP,KSPFischerGuess*);

PETSC_EXTERN PetscErrorCode MatCreateSchurComplement(Mat,Mat,Mat,Mat,Mat,Mat*);
PETSC_EXTERN PetscErrorCode MatSchurComplementGetKSP(Mat,KSP*);
PETSC_EXTERN PetscErrorCode MatSchurComplementSetKSP(Mat,KSP);
PETSC_EXTERN PetscErrorCode MatSchurComplementSet(Mat,Mat,Mat,Mat,Mat,Mat);
PETSC_EXTERN PetscErrorCode MatSchurComplementUpdate(Mat,Mat,Mat,Mat,Mat,Mat,MatStructure);
PETSC_EXTERN PetscErrorCode MatSchurComplementGetSubmatrices(Mat,Mat*,Mat*,Mat*,Mat*,Mat*);
PETSC_EXTERN PetscErrorCode MatSchurComplementComputeExplicitOperator(Mat,Mat*);
PETSC_EXTERN PetscErrorCode MatGetSchurComplement(Mat,IS,IS,IS,IS,MatReuse,Mat *,MatReuse,Mat *);

PETSC_EXTERN PetscErrorCode KSPSetDM(KSP,DM);
PETSC_EXTERN PetscErrorCode KSPSetDMActive(KSP,PetscBool );
PETSC_EXTERN PetscErrorCode KSPGetDM(KSP,DM*);
PETSC_EXTERN PetscErrorCode KSPSetApplicationContext(KSP,void*);
PETSC_EXTERN PetscErrorCode KSPGetApplicationContext(KSP,void*);
PETSC_EXTERN PetscErrorCode KSPSetComputeRHS(KSP,PetscErrorCode (*func)(KSP,Vec,void*),void *);
PETSC_EXTERN PetscErrorCode KSPSetComputeOperators(KSP,PetscErrorCode(*)(KSP,Mat,Mat,MatStructure*,void*),void*);
PETSC_EXTERN PetscErrorCode KSPSetComputeInitialGuess(KSP,PetscErrorCode(*)(KSP,Vec,void*),void*);
PETSC_EXTERN PetscErrorCode DMKSPSetComputeOperators(DM,PetscErrorCode(*)(KSP,Mat,Mat,MatStructure*,void*),void*);
PETSC_EXTERN PetscErrorCode DMKSPGetComputeOperators(DM,PetscErrorCode(**)(KSP,Mat,Mat,MatStructure*,void*),void*);
PETSC_EXTERN PetscErrorCode DMKSPSetComputeRHS(DM,PetscErrorCode(*)(KSP,Vec,void*),void*);
PETSC_EXTERN PetscErrorCode DMKSPGetComputeRHS(DM,PetscErrorCode(**)(KSP,Vec,void*),void*);
PETSC_EXTERN PetscErrorCode DMKSPSetComputeInitialGuess(DM,PetscErrorCode(*)(KSP,Vec,void*),void*);
PETSC_EXTERN PetscErrorCode DMKSPGetComputeInitialGuess(DM,PetscErrorCode(**)(KSP,Vec,void*),void*);

#endif