/*
SVD routines for setting solver options.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
SLEPc - Scalable Library for Eigenvalue Problem Computations
Copyright (c) 2002-2011, Universitat Politecnica de Valencia, Spain
This file is part of SLEPc.
SLEPc is free software: you can redistribute it and/or modify it under the
terms of version 3 of the GNU Lesser General Public License as published by
the Free Software Foundation.
SLEPc is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for
more details.
You should have received a copy of the GNU Lesser General Public License
along with SLEPc. If not, see <http://www.gnu.org/licenses/>.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
*/
#include <private/svdimpl.h> /*I "slepcsvd.h" I*/
#undef __FUNCT__
#define __FUNCT__ "SVDSetTransposeMode"
/*@
SVDSetTransposeMode - Sets how to handle the transpose of the matrix
associated with the singular value problem.
Logically Collective on SVD
Input Parameters:
+ svd - the singular value solver context
- mode - how to compute the transpose, one of SVD_TRANSPOSE_EXPLICIT
or SVD_TRANSPOSE_IMPLICIT (see notes below)
Options Database Key:
. -svd_transpose_mode <mode> - Indicates the mode flag, where <mode>
is one of 'explicit' or 'implicit'.
Notes:
In the SVD_TRANSPOSE_EXPLICIT mode, the transpose of the matrix is
explicitly built.
The option SVD_TRANSPOSE_IMPLICIT does not build the transpose, but
handles it implicitly via MatMultTranspose() operations. This is
likely to be more inefficient than SVD_TRANSPOSE_EXPLICIT, both in
sequential and in parallel, but requires less storage.
The default is SVD_TRANSPOSE_EXPLICIT if the matrix has defined the
MatTranspose operation, and SVD_TRANSPOSE_IMPLICIT otherwise.
Level: advanced
.seealso: SVDGetTransposeMode(), SVDSolve(), SVDSetOperator(),
SVDGetOperator(), SVDTransposeMode
@*/
PetscErrorCode SVDSetTransposeMode(SVD svd,SVDTransposeMode mode)
{
PetscFunctionBegin;
PetscValidHeaderSpecific(svd,SVD_CLASSID,1);
PetscValidLogicalCollectiveEnum(svd,mode,2);
if (mode == PETSC_DEFAULT || mode == PETSC_DECIDE) mode = (SVDTransposeMode)PETSC_DECIDE;
else switch (mode) {
case SVD_TRANSPOSE_EXPLICIT:
case SVD_TRANSPOSE_IMPLICIT:
if (svd->transmode!=mode) {
svd->transmode = mode;
svd->setupcalled = 0;
}
break;
default:
SETERRQ(((PetscObject)svd)->comm,PETSC_ERR_ARG_OUTOFRANGE,"Invalid transpose mode");
}
PetscFunctionReturn(0);
}
#undef __FUNCT__
#define __FUNCT__ "SVDGetTransposeMode"
/*@C
SVDGetTransposeMode - Gets the mode used to compute the transpose
of the matrix associated with the singular value problem.
Not Collective
Input Parameter:
. svd - the singular value solver context
Output paramter:
. mode - how to compute the transpose, one of SVD_TRANSPOSE_EXPLICIT
or SVD_TRANSPOSE_IMPLICIT
Level: advanced
.seealso: SVDSetTransposeMode(), SVDSolve(), SVDSetOperator(),
SVDGetOperator(), SVDTransposeMode
@*/
PetscErrorCode SVDGetTransposeMode(SVD svd,SVDTransposeMode *mode)
{
PetscFunctionBegin;
PetscValidHeaderSpecific(svd,SVD_CLASSID,1);
PetscValidPointer(mode,2);
*mode = svd->transmode;
PetscFunctionReturn(0);
}
#undef __FUNCT__
#define __FUNCT__ "SVDSetTolerances"
/*@
SVDSetTolerances - Sets the tolerance and maximum
iteration count used by the default SVD convergence testers.
Logically Collective on SVD
Input Parameters:
+ svd - the singular value solver context
. tol - the convergence tolerance
- maxits - maximum number of iterations to use
Options Database Keys:
+ -svd_tol <tol> - Sets the convergence tolerance
- -svd_max_it <maxits> - Sets the maximum number of iterations allowed
(use PETSC_DECIDE to compute an educated guess based on basis and matrix sizes)
Notes:
Use PETSC_IGNORE to retain the previous value of any parameter.
Level: intermediate
.seealso: SVDGetTolerances()
@*/
PetscErrorCode SVDSetTolerances(SVD svd,PetscReal tol,PetscInt maxits)
{
PetscFunctionBegin;
PetscValidHeaderSpecific(svd,SVD_CLASSID,1);
PetscValidLogicalCollectiveReal(svd,tol,2);
PetscValidLogicalCollectiveInt(svd,maxits,3);
if (tol != PETSC_IGNORE) {
if (tol == PETSC_DEFAULT) {
tol = PETSC_DEFAULT;
} else {
if (tol < 0.0) SETERRQ(((PetscObject)svd)->comm,PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of tol. Must be > 0");
svd->tol = tol;
}
}
if (maxits != PETSC_IGNORE) {
if (maxits == PETSC_DEFAULT || maxits == PETSC_DECIDE) {
svd->max_it = 0;
svd->setupcalled = 0;
} else {
if (maxits < 0) SETERRQ(((PetscObject)svd)->comm,PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of maxits. Must be > 0");
svd->max_it = maxits;
}
}
PetscFunctionReturn(0);
}
#undef __FUNCT__
#define __FUNCT__ "SVDGetTolerances"
/*@
SVDGetTolerances - Gets the tolerance and maximum
iteration count used by the default SVD convergence tests.
Not Collective
Input Parameter:
. svd - the singular value solver context
Output Parameters:
+ tol - the convergence tolerance
- maxits - maximum number of iterations
Notes:
The user can specify PETSC_NULL for any parameter that is not needed.
Level: intermediate
.seealso: SVDSetTolerances()
@*/
PetscErrorCode SVDGetTolerances(SVD svd,PetscReal *tol,PetscInt *maxits)
{
PetscFunctionBegin;
PetscValidHeaderSpecific(svd,SVD_CLASSID,1);
if (tol) *tol = svd->tol;
if (maxits) *maxits = svd->max_it;
PetscFunctionReturn(0);
}
#undef __FUNCT__
#define __FUNCT__ "SVDSetDimensions"
/*@
SVDSetDimensions - Sets the number of singular values to compute
and the dimension of the subspace.
Logically Collective on SVD
Input Parameters:
+ svd - the singular value solver context
. nsv - number of singular values to compute
. ncv - the maximum dimension of the subspace to be used by the solver
- mpd - the maximum dimension allowed for the projected problem
Options Database Keys:
+ -svd_nsv <nsv> - Sets the number of singular values
. -svd_ncv <ncv> - Sets the dimension of the subspace
- -svd_mpd <mpd> - Sets the maximum projected dimension
Notes:
Use PETSC_IGNORE to retain the previous value of any parameter.
Use PETSC_DECIDE for ncv and mpd to assign a reasonably good value, which is
dependent on the solution method and the number of singular values required.
The parameters ncv and mpd are intimately related, so that the user is advised
to set one of them at most. Normal usage is that
(a) in cases where nsv is small, the user sets ncv (a reasonable default is 2*nsv); and
(b) in cases where nsv is large, the user sets mpd.
The value of ncv should always be between nsv and (nsv+mpd), typically
ncv=nsv+mpd. If nev is not too large, mpd=nsv is a reasonable choice, otherwise
a smaller value should be used.
Level: intermediate
.seealso: SVDGetDimensions()
@*/
PetscErrorCode SVDSetDimensions(SVD svd,PetscInt nsv,PetscInt ncv,PetscInt mpd)
{
PetscFunctionBegin;
PetscValidHeaderSpecific(svd,SVD_CLASSID,1);
PetscValidLogicalCollectiveInt(svd,nsv,2);
PetscValidLogicalCollectiveInt(svd,ncv,3);
PetscValidLogicalCollectiveInt(svd,mpd,4);
if (nsv != PETSC_IGNORE) {
if (nsv<1) SETERRQ(((PetscObject)svd)->comm,PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of nsv. Must be > 0");
svd->nsv = nsv;
}
if (ncv != PETSC_IGNORE) {
if (ncv == PETSC_DEFAULT || ncv == PETSC_DECIDE) {
svd->ncv = 0;
} else {
if (ncv<1) SETERRQ(((PetscObject)svd)->comm,PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of ncv. Must be > 0");
svd->ncv = ncv;
}
svd->setupcalled = 0;
}
if (mpd != PETSC_IGNORE) {
if (mpd == PETSC_DECIDE || mpd == PETSC_DEFAULT) {
svd->mpd = 0;
} else {
if (mpd<1) SETERRQ(((PetscObject)svd)->comm,PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of mpd. Must be > 0");
svd->mpd = mpd;
}
}
PetscFunctionReturn(0);
}
#undef __FUNCT__
#define __FUNCT__ "SVDGetDimensions"
/*@
SVDGetDimensions - Gets the number of singular values to compute
and the dimension of the subspace.
Not Collective
Input Parameter:
. svd - the singular value context
Output Parameters:
+ nsv - number of singular values to compute
. ncv - the maximum dimension of the subspace to be used by the solver
- mpd - the maximum dimension allowed for the projected problem
Notes:
The user can specify PETSC_NULL for any parameter that is not needed.
Level: intermediate
.seealso: SVDSetDimensions()
@*/
PetscErrorCode SVDGetDimensions(SVD svd,PetscInt *nsv,PetscInt *ncv,PetscInt *mpd)
{
PetscFunctionBegin;
PetscValidHeaderSpecific(svd,SVD_CLASSID,1);
if (nsv) *nsv = svd->nsv;
if (ncv) *ncv = svd->ncv;
if (mpd) *mpd = svd->mpd;
PetscFunctionReturn(0);
}
#undef __FUNCT__
#define __FUNCT__ "SVDSetWhichSingularTriplets"
/*@
SVDSetWhichSingularTriplets - Specifies which singular triplets are
to be sought.
Logically Collective on SVD
Input Parameter:
. svd - singular value solver context obtained from SVDCreate()
Output Parameter:
. which - which singular triplets are to be sought
Possible values:
The parameter 'which' can have one of these values:
+ SVD_LARGEST - largest singular values
- SVD_SMALLEST - smallest singular values
Options Database Keys:
+ -svd_largest - Sets largest singular values
- -svd_smallest - Sets smallest singular values
Level: intermediate
.seealso: SVDGetWhichSingularTriplets(), SVDWhich
@*/
PetscErrorCode SVDSetWhichSingularTriplets(SVD svd,SVDWhich which)
{
PetscFunctionBegin;
PetscValidHeaderSpecific(svd,SVD_CLASSID,1);
PetscValidLogicalCollectiveEnum(svd,which,2);
switch (which) {
case SVD_LARGEST:
case SVD_SMALLEST:
if (svd->which != which) {
svd->setupcalled = 0;
svd->which = which;
}
break;
default:
SETERRQ(((PetscObject)svd)->comm,PETSC_ERR_ARG_OUTOFRANGE,"Invalid 'which' parameter");
}
PetscFunctionReturn(0);
}
#undef __FUNCT__
#define __FUNCT__ "SVDGetWhichSingularTriplets"
/*@C
SVDGetWhichSingularTriplets - Returns which singular triplets are
to be sought.
Not Collective
Input Parameter:
. svd - singular value solver context obtained from SVDCreate()
Output Parameter:
. which - which singular triplets are to be sought
Notes:
See SVDSetWhichSingularTriplets() for possible values of which
Level: intermediate
.seealso: SVDSetWhichSingularTriplets(), SVDWhich
@*/
PetscErrorCode SVDGetWhichSingularTriplets(SVD svd,SVDWhich *which)
{
PetscFunctionBegin;
PetscValidHeaderSpecific(svd,SVD_CLASSID,1);
PetscValidPointer(which,2);
*which = svd->which;
PetscFunctionReturn(0);
}
#undef __FUNCT__
#define __FUNCT__ "SVDSetFromOptions"
/*@
SVDSetFromOptions - Sets SVD options from the options database.
This routine must be called before SVDSetUp() if the user is to be
allowed to set the solver type.
Collective on SVD
Input Parameters:
. svd - the singular value solver context
Notes:
To see all options, run your program with the -help option.
Level: beginner
.seealso:
@*/
PetscErrorCode SVDSetFromOptions(SVD svd)
{
PetscErrorCode ierr;
char type[256],monfilename[PETSC_MAX_PATH_LEN];
PetscBool flg;
const char *mode_list[2] = {"explicit","implicit"};
PetscInt i,j,k;
PetscReal r;
PetscViewer monviewer;
SlepcConvMonitor ctx;
PetscFunctionBegin;
PetscValidHeaderSpecific(svd,SVD_CLASSID,1);
svd->setupcalled = 0;
if (!SVDRegisterAllCalled) { ierr = SVDRegisterAll(PETSC_NULL);CHKERRQ(ierr); }
ierr = PetscOptionsBegin(((PetscObject)svd)->comm,((PetscObject)svd)->prefix,"Singular Value Solver (SVD) Options","SVD");CHKERRQ(ierr);
ierr = PetscOptionsList("-svd_type","Singular Value Solver method","SVDSetType",SVDList,(char*)(((PetscObject)svd)->type_name?((PetscObject)svd)->type_name:SVDCROSS),type,256,&flg);CHKERRQ(ierr);
if (flg) {
ierr = SVDSetType(svd,type);CHKERRQ(ierr);
} else if (!((PetscObject)svd)->type_name) {
ierr = SVDSetType(svd,SVDCROSS);CHKERRQ(ierr);
}
ierr = PetscOptionsName("-svd_view","Print detailed information on solver used","SVDView",&flg);CHKERRQ(ierr);
ierr = PetscOptionsEList("-svd_transpose_mode","Transpose SVD mode","SVDSetTransposeMode",mode_list,2,svd->transmode == PETSC_DECIDE ? "decide" : mode_list[svd->transmode],&i,&flg);CHKERRQ(ierr);
if (flg) {
ierr = SVDSetTransposeMode(svd,(SVDTransposeMode)i);CHKERRQ(ierr);
}
r = i = PETSC_IGNORE;
ierr = PetscOptionsInt("-svd_max_it","Maximum number of iterations","SVDSetTolerances",svd->max_it,&i,PETSC_NULL);CHKERRQ(ierr);
ierr = PetscOptionsReal("-svd_tol","Tolerance","SVDSetTolerances",svd->tol==PETSC_DEFAULT?SLEPC_DEFAULT_TOL:svd->tol,&r,PETSC_NULL);CHKERRQ(ierr);
ierr = SVDSetTolerances(svd,r,i);CHKERRQ(ierr);
i = j = k = PETSC_IGNORE;
ierr = PetscOptionsInt("-svd_nsv","Number of singular values to compute","SVDSetDimensions",svd->nsv,&i,PETSC_NULL);CHKERRQ(ierr);
ierr = PetscOptionsInt("-svd_ncv","Number of basis vectors","SVDSetDimensions",svd->ncv,&j,PETSC_NULL);CHKERRQ(ierr);
ierr = PetscOptionsInt("-svd_mpd","Maximum dimension of projected problem","SVDSetDimensions",svd->mpd,&k,PETSC_NULL);CHKERRQ(ierr);
ierr = SVDSetDimensions(svd,i,j,k);CHKERRQ(ierr);
ierr = PetscOptionsBoolGroupBegin("-svd_largest","compute largest singular values","SVDSetWhichSingularTriplets",&flg);CHKERRQ(ierr);
if (flg) { ierr = SVDSetWhichSingularTriplets(svd,SVD_LARGEST);CHKERRQ(ierr); }
ierr = PetscOptionsBoolGroupEnd("-svd_smallest","compute smallest singular values","SVDSetWhichSingularTriplets",&flg);CHKERRQ(ierr);
if (flg) { ierr = SVDSetWhichSingularTriplets(svd,SVD_SMALLEST);CHKERRQ(ierr); }
flg = PETSC_FALSE;
ierr = PetscOptionsBool("-svd_monitor_cancel","Remove any hardwired monitor routines","SVDMonitorCancel",flg,&flg,PETSC_NULL);CHKERRQ(ierr);
if (flg) {
ierr = SVDMonitorCancel(svd);CHKERRQ(ierr);
}
ierr = PetscOptionsString("-svd_monitor_all","Monitor approximate singular values and error estimates","SVDMonitorSet","stdout",monfilename,PETSC_MAX_PATH_LEN,&flg);CHKERRQ(ierr);
if (flg) {
ierr = PetscViewerASCIIOpen(((PetscObject)svd)->comm,monfilename,&monviewer);CHKERRQ(ierr);
ierr = SVDMonitorSet(svd,SVDMonitorAll,monviewer,(PetscErrorCode (*)(void**))PetscViewerDestroy);CHKERRQ(ierr);
ierr = SVDSetTrackAll(svd,PETSC_TRUE);CHKERRQ(ierr);
}
ierr = PetscOptionsString("-svd_monitor_conv","Monitor approximate singular values and error estimates as they converge","SVDMonitorSet","stdout",monfilename,PETSC_MAX_PATH_LEN,&flg);CHKERRQ(ierr);
if (flg) {
ierr = PetscNew(struct _n_SlepcConvMonitor,&ctx);CHKERRQ(ierr);
ierr = PetscViewerASCIIOpen(((PetscObject)svd)->comm,monfilename,&ctx->viewer);CHKERRQ(ierr);
ierr = SVDMonitorSet(svd,SVDMonitorConverged,ctx,(PetscErrorCode (*)(void**))SlepcConvMonitorDestroy);CHKERRQ(ierr);
}
ierr = PetscOptionsString("-svd_monitor","Monitor first unconverged approximate singular value and error estimate","SVDMonitorSet","stdout",monfilename,PETSC_MAX_PATH_LEN,&flg);CHKERRQ(ierr);
if (flg) {
ierr = PetscViewerASCIIOpen(((PetscObject)svd)->comm,monfilename,&monviewer);CHKERRQ(ierr);
ierr = SVDMonitorSet(svd,SVDMonitorFirst,monviewer,(PetscErrorCode (*)(void**))PetscViewerDestroy);CHKERRQ(ierr);
}
flg = PETSC_FALSE;
ierr = PetscOptionsBool("-svd_monitor_draw","Monitor first unconverged approximate singular value and error estimate graphically","SVDMonitorSet",flg,&flg,PETSC_NULL);CHKERRQ(ierr);
if (flg) {
ierr = SVDMonitorSet(svd,SVDMonitorLG,PETSC_NULL,PETSC_NULL);CHKERRQ(ierr);
}
flg = PETSC_FALSE;
ierr = PetscOptionsBool("-svd_monitor_draw_all","Monitor error estimates graphically","SVDMonitorSet",flg,&flg,PETSC_NULL);CHKERRQ(ierr);
if (flg) {
ierr = SVDMonitorSet(svd,SVDMonitorLGAll,PETSC_NULL,PETSC_NULL);CHKERRQ(ierr);
ierr = SVDSetTrackAll(svd,PETSC_TRUE);CHKERRQ(ierr);
}
if (svd->ops->setfromoptions) {
ierr = (*svd->ops->setfromoptions)(svd);CHKERRQ(ierr);
}
ierr = PetscObjectProcessOptionsHandlers((PetscObject)svd);CHKERRQ(ierr);
ierr = PetscOptionsEnd();CHKERRQ(ierr);
if (!svd->ip) { ierr = SVDGetIP(svd,&svd->ip);CHKERRQ(ierr); }
ierr = IPSetFromOptions(svd->ip);CHKERRQ(ierr);
ierr = PetscRandomSetFromOptions(svd->rand);CHKERRQ(ierr);
PetscFunctionReturn(0);
}
#undef __FUNCT__
#define __FUNCT__ "SVDSetTrackAll"
/*@
SVDSetTrackAll - Specifies if the solver must compute the residual norm of all
approximate singular value or not.
Logically Collective on SVD
Input Parameters:
+ svd - the singular value solver context
- trackall - whether to compute all residuals or not
Notes:
If the user sets trackall=PETSC_TRUE then the solver computes (or estimates)
the residual norm for each singular value approximation. Computing the residual is
usually an expensive operation and solvers commonly compute only the residual
associated to the first unconverged singular value.
The options '-svd_monitor_all' and '-svd_monitor_draw_all' automatically
activate this option.
Level: intermediate
.seealso: SVDGetTrackAll()
@*/
PetscErrorCode SVDSetTrackAll(SVD svd,PetscBool trackall)
{
PetscFunctionBegin;
PetscValidHeaderSpecific(svd,SVD_CLASSID,1);
PetscValidLogicalCollectiveBool(svd,trackall,2);
svd->trackall = trackall;
PetscFunctionReturn(0);
}
#undef __FUNCT__
#define __FUNCT__ "SVDGetTrackAll"
/*@
SVDGetTrackAll - Returns the flag indicating whether all residual norms must
be computed or not.
Not Collective
Input Parameter:
. svd - the singular value solver context
Output Parameter:
. trackall - the returned flag
Level: intermediate
.seealso: SVDSetTrackAll()
@*/
PetscErrorCode SVDGetTrackAll(SVD svd,PetscBool *trackall)
{
PetscFunctionBegin;
PetscValidHeaderSpecific(svd,SVD_CLASSID,1);
PetscValidPointer(trackall,2);
*trackall = svd->trackall;
PetscFunctionReturn(0);
}
#undef __FUNCT__
#define __FUNCT__ "SVDSetOptionsPrefix"
/*@C
SVDSetOptionsPrefix - Sets the prefix used for searching for all
SVD options in the database.
Logically Collective on SVD
Input Parameters:
+ svd - the singular value solver context
- prefix - the prefix string to prepend to all SVD option requests
Notes:
A hyphen (-) must NOT be given at the beginning of the prefix name.
The first character of all runtime options is AUTOMATICALLY the
hyphen.
For example, to distinguish between the runtime options for two
different SVD contexts, one could call
.vb
SVDSetOptionsPrefix(svd1,"svd1_")
SVDSetOptionsPrefix(svd2,"svd2_")
.ve
Level: advanced
.seealso: SVDAppendOptionsPrefix(), SVDGetOptionsPrefix()
@*/
PetscErrorCode SVDSetOptionsPrefix(SVD svd,const char *prefix)
{
PetscErrorCode ierr;
PetscBool flg1,flg2;
EPS eps;
PetscFunctionBegin;
PetscValidHeaderSpecific(svd,SVD_CLASSID,1);
ierr = PetscObjectSetOptionsPrefix((PetscObject)svd,prefix);CHKERRQ(ierr);
ierr = PetscTypeCompare((PetscObject)svd,SVDCROSS,&flg1);CHKERRQ(ierr);
ierr = PetscTypeCompare((PetscObject)svd,SVDCYCLIC,&flg2);CHKERRQ(ierr);
if (flg1) {
ierr = SVDCrossGetEPS(svd,&eps);CHKERRQ(ierr);
} else if (flg2) {
ierr = SVDCyclicGetEPS(svd,&eps);CHKERRQ(ierr);
}
if (flg1 || flg2) {
ierr = EPSSetOptionsPrefix(eps,prefix);CHKERRQ(ierr);
ierr = EPSAppendOptionsPrefix(eps,"svd_");CHKERRQ(ierr);
}
PetscFunctionReturn(0);
}
#undef __FUNCT__
#define __FUNCT__ "SVDAppendOptionsPrefix"
/*@C
SVDAppendOptionsPrefix - Appends to the prefix used for searching for all
SVD options in the database.
Logically Collective on SVD
Input Parameters:
+ svd - the singular value solver context
- prefix - the prefix string to prepend to all SVD option requests
Notes:
A hyphen (-) must NOT be given at the beginning of the prefix name.
The first character of all runtime options is AUTOMATICALLY the hyphen.
Level: advanced
.seealso: SVDSetOptionsPrefix(), SVDGetOptionsPrefix()
@*/
PetscErrorCode SVDAppendOptionsPrefix(SVD svd,const char *prefix)
{
PetscErrorCode ierr;
PetscBool flg1,flg2;
EPS eps;
PetscFunctionBegin;
PetscValidHeaderSpecific(svd,SVD_CLASSID,1);
ierr = PetscObjectAppendOptionsPrefix((PetscObject)svd,prefix);CHKERRQ(ierr);
ierr = PetscTypeCompare((PetscObject)svd,SVDCROSS,&flg1);CHKERRQ(ierr);
ierr = PetscTypeCompare((PetscObject)svd,SVDCYCLIC,&flg2);CHKERRQ(ierr);
if (flg1) {
ierr = SVDCrossGetEPS(svd,&eps);CHKERRQ(ierr);
} else if (flg2) {
ierr = SVDCyclicGetEPS(svd,&eps);CHKERRQ(ierr);
}
if (flg1 || flg2) {
ierr = EPSSetOptionsPrefix(eps,((PetscObject)svd)->prefix);CHKERRQ(ierr);
ierr = EPSAppendOptionsPrefix(eps,"svd_");CHKERRQ(ierr);
}
PetscFunctionReturn(0);
}
#undef __FUNCT__
#define __FUNCT__ "SVDGetOptionsPrefix"
/*@C
SVDGetOptionsPrefix - Gets the prefix used for searching for all
SVD options in the database.
Not Collective
Input Parameters:
. svd - the singular value solver context
Output Parameters:
. prefix - pointer to the prefix string used is returned
Notes: On the fortran side, the user should pass in a string 'prefix' of
sufficient length to hold the prefix.
Level: advanced
.seealso: SVDSetOptionsPrefix(), SVDAppendOptionsPrefix()
@*/
PetscErrorCode SVDGetOptionsPrefix(SVD svd,const char *prefix[])
{
PetscErrorCode ierr;
PetscFunctionBegin;
PetscValidHeaderSpecific(svd,SVD_CLASSID,1);
PetscValidPointer(prefix,2);
ierr = PetscObjectGetOptionsPrefix((PetscObject)svd,prefix);CHKERRQ(ierr);
PetscFunctionReturn(0);
}