Subversion Repositories slepc-dev

/*

    The ST (spectral transformation) interface routines, callable by users.

   - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

   SLEPc - Scalable Library for Eigenvalue Problem Computations

   Copyright (c) 2002-2010, Universidad 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/stimpl.h>            /*I "slepcst.h" I*/

PetscClassId     ST_CLASSID = 0;

PetscLogEvent    ST_SetUp = 0, ST_Apply = 0, ST_ApplyTranspose = 0;

static PetscBool STPackageInitialized = PETSC_FALSE;

#undef __FUNCT__  

#define __FUNCT__ "STFinalizePackage"

/*@C

   STFinalizePackage - This function destroys everything in the Slepc interface

   to the ST package. It is called from SlepcFinalize().

   Level: developer

.seealso: SlepcFinalize()

@*/

PetscErrorCode STFinalizePackage(void)

{

  PetscFunctionBegin;

  STPackageInitialized = PETSC_FALSE;

  STList               = 0;

  PetscFunctionReturn(0);

}

#undef __FUNCT__  

#define __FUNCT__ "STInitializePackage"

/*@C

   STInitializePackage - This function initializes everything in the ST package. It is called

   from PetscDLLibraryRegister() when using dynamic libraries, and on the first call to STCreate()

   when using static libraries.

   Input Parameter:

.  path - The dynamic library path, or PETSC_NULL

   Level: developer

.seealso: SlepcInitialize()

@*/

PetscErrorCode STInitializePackage(const char *path)

{

  char           logList[256];

  char           *className;

  PetscBool      opt;

  PetscErrorCode ierr;

  PetscFunctionBegin;

  if (STPackageInitialized) PetscFunctionReturn(0);

  STPackageInitialized = PETSC_TRUE;

  /* Register Classes */

  ierr = PetscClassIdRegister("Spectral Transform",&ST_CLASSID);CHKERRQ(ierr);

  /* Register Constructors */

  ierr = STRegisterAll(path);CHKERRQ(ierr);

  /* Register Events */

  ierr = PetscLogEventRegister("STSetUp",ST_CLASSID,&ST_SetUp);CHKERRQ(ierr);

  ierr = PetscLogEventRegister("STApply",ST_CLASSID,&ST_Apply);CHKERRQ(ierr);

  ierr = PetscLogEventRegister("STApplyTranspose",ST_CLASSID,&ST_ApplyTranspose); CHKERRQ(ierr);

  /* Process info exclusions */

  ierr = PetscOptionsGetString(PETSC_NULL, "-info_exclude", logList, 256, &opt);CHKERRQ(ierr);

  if (opt) {

    ierr = PetscStrstr(logList, "st", &className);CHKERRQ(ierr);

    if (className) {

      ierr = PetscInfoDeactivateClass(ST_CLASSID);CHKERRQ(ierr);

    }

  }

  /* Process summary exclusions */

  ierr = PetscOptionsGetString(PETSC_NULL, "-log_summary_exclude", logList, 256, &opt);CHKERRQ(ierr);

  if (opt) {

    ierr = PetscStrstr(logList, "st", &className);CHKERRQ(ierr);

    if (className) {

      ierr = PetscLogEventDeactivateClass(ST_CLASSID);CHKERRQ(ierr);

    }

  }

  ierr = PetscRegisterFinalize(STFinalizePackage);CHKERRQ(ierr);

  PetscFunctionReturn(0);

}

#undef __FUNCT__  

#define __FUNCT__ "STDestroy"

/*@C

   STDestroy - Destroys ST context that was created with STCreate().

   Collective on ST

   Input Parameter:

.  st - the spectral transformation context

   Level: beginner

.seealso: STCreate(), STSetUp()

@*/

PetscErrorCode STDestroy(ST *st)

{

  PetscErrorCode ierr;

  PetscFunctionBegin;

  if (!*st) PetscFunctionReturn(0);

  PetscValidHeaderSpecific(*st,ST_CLASSID,1);

  if (--((PetscObject)(*st))->refct > 0) { *st = 0; PetscFunctionReturn(0); }

  ierr = PetscObjectDepublish(*st);CHKERRQ(ierr);

  if ((*st)->ops->destroy) {

    ierr = (*(*st)->ops->destroy)(*st);CHKERRQ(ierr);

  }

  ierr = MatDestroy(&(*st)->A);CHKERRQ(ierr);

  ierr = MatDestroy(&(*st)->B);CHKERRQ(ierr);

  ierr = KSPDestroy(&(*st)->ksp);CHKERRQ(ierr);

  ierr = VecDestroy(&(*st)->w);CHKERRQ(ierr);

  ierr = VecDestroy(&(*st)->D);CHKERRQ(ierr);

  ierr = VecDestroy(&(*st)->wb);CHKERRQ(ierr);

  if ((*st)->shift_matrix != ST_MATMODE_INPLACE) {

    ierr = MatDestroy(&(*st)->mat);CHKERRQ(ierr);

  }

  ierr = PetscHeaderDestroy(st);CHKERRQ(ierr);

  PetscFunctionReturn(0);

}

#undef __FUNCT__  

#define __FUNCT__ "STCreate"

/*@C

   STCreate - Creates a spectral transformation context.

   Collective on MPI_Comm

   Input Parameter:

.  comm - MPI communicator

   Output Parameter:

.  st - location to put the spectral transformation context

   Level: beginner

.seealso: STSetUp(), STApply(), STDestroy(), ST

@*/

PetscErrorCode STCreate(MPI_Comm comm,ST *newst)

{

  PetscErrorCode ierr;

  ST             st;

  const char     *prefix;

  PetscFunctionBegin;

  PetscValidPointer(newst,2);

  *newst = 0;

  ierr = PetscHeaderCreate(st,_p_ST,struct _STOps,ST_CLASSID,-1,"ST",comm,STDestroy,STView);CHKERRQ(ierr);

  ierr = PetscMemzero(st->ops,sizeof(struct _STOps));CHKERRQ(ierr);

  st->A                   = 0;

  st->B                   = 0;

  st->sigma               = 0.0;

  st->sigma_set           = PETSC_FALSE;

  st->defsigma            = 0.0;

  st->data                = 0;

  st->setupcalled         = 0;

  st->w                   = 0;

  st->D                   = 0;

  st->wb                  = 0;

  st->mat                 = 0;

  st->shift_matrix        = ST_MATMODE_COPY;

  st->str                 = DIFFERENT_NONZERO_PATTERN;

  ierr = KSPCreate(((PetscObject)st)->comm,&st->ksp);CHKERRQ(ierr);

  ierr = STGetOptionsPrefix(st,&prefix);CHKERRQ(ierr);

  ierr = KSPSetOptionsPrefix(st->ksp,prefix);CHKERRQ(ierr);

  ierr = KSPAppendOptionsPrefix(st->ksp,"st_");CHKERRQ(ierr);

  ierr = PetscObjectIncrementTabLevel((PetscObject)st->ksp,(PetscObject)st,1);CHKERRQ(ierr);

  *newst                  = st;

  PetscFunctionReturn(0);

}

#undef __FUNCT__  

#define __FUNCT__ "STSetOperators"

/*@

   STSetOperators - Sets the matrices associated with the eigenvalue problem.

   Collective on ST and Mat

   Input Parameters:

+  st - the spectral transformation context

.  A  - the matrix associated with the eigensystem

-  B  - the second matrix in the case of generalized eigenproblems

   Notes:

   To specify a standard eigenproblem, use PETSC_NULL for B.

   Level: intermediate

.seealso: STGetOperators()

 @*/

PetscErrorCode STSetOperators(ST st,Mat A,Mat B)

{

  PetscErrorCode ierr;

  PetscFunctionBegin;

  PetscValidHeaderSpecific(st,ST_CLASSID,1);

  PetscValidHeaderSpecific(A,MAT_CLASSID,2);

  if (B) PetscValidHeaderSpecific(B,MAT_CLASSID,3);

  PetscCheckSameComm(st,1,A,2);

  if (B) PetscCheckSameComm(st,1,B,3);

  ierr = PetscObjectReference((PetscObject)A);CHKERRQ(ierr);

  ierr = MatDestroy(&st->A);CHKERRQ(ierr);

  st->A = A;

  if (B) { ierr = PetscObjectReference((PetscObject)B);CHKERRQ(ierr); }

  ierr = MatDestroy(&st->B);CHKERRQ(ierr);

  st->B = B;

  st->setupcalled = 0;

  PetscFunctionReturn(0);

}

#undef __FUNCT__  

#define __FUNCT__ "STGetOperators"

/*@C

   STGetOperators - Gets the matrices associated with the eigensystem.

   Not collective, though parallel Mats are returned if the ST is parallel

   Input Parameter:

.  st - the spectral transformation context

   Output Parameters:

.  A - the matrix associated with the eigensystem

-  B - the second matrix in the case of generalized eigenproblems

   Level: intermediate

.seealso: STSetOperators()

@*/

PetscErrorCode STGetOperators(ST st,Mat *A,Mat *B)

{

  PetscFunctionBegin;

  PetscValidHeaderSpecific(st,ST_CLASSID,1);

  if (A) *A = st->A;

  if (B) *B = st->B;

  PetscFunctionReturn(0);

}

#undef __FUNCT__  

#define __FUNCT__ "STSetShift"

/*@

   STSetShift - Sets the shift associated with the spectral transformation.

   Collective on ST

   Input Parameters:

+  st - the spectral transformation context

-  shift - the value of the shift

   Note:

   In some spectral transformations, changing the shift may have associated

   a lot of work, for example recomputing a factorization.

   Level: beginner

@*/

PetscErrorCode STSetShift(ST st,PetscScalar shift)

{

  PetscErrorCode ierr;

  PetscFunctionBegin;

  PetscValidHeaderSpecific(st,ST_CLASSID,1);

  PetscValidLogicalCollectiveScalar(st,shift,2);

  if (st->sigma != shift) {

    if (st->ops->setshift) {

      ierr = (*st->ops->setshift)(st,shift); CHKERRQ(ierr);

    }

  }

  st->sigma = shift;

  st->sigma_set = PETSC_TRUE;

  PetscFunctionReturn(0);

}

#undef __FUNCT__  

#define __FUNCT__ "STGetShift"

/*@

   STGetShift - Gets the shift associated with the spectral transformation.

   Not collective

   Input Parameter:

.  st - the spectral transformation context

   Output Parameter:

.  shift - the value of the shift

   Level: beginner

@*/

PetscErrorCode STGetShift(ST st,PetscScalar* shift)

{

  PetscFunctionBegin;

  PetscValidHeaderSpecific(st,ST_CLASSID,1);

  PetscValidScalarPointer(shift,2);

  *shift = st->sigma;

  PetscFunctionReturn(0);

}

#undef __FUNCT__  

#define __FUNCT__ "STSetDefaultShift"

/*@

   STSetDefaultShift - Sets the value of the shift that should be employed if

   the user did not specify one.

   Collective on ST

   Input Parameters:

+  st - the spectral transformation context

-  defaultshift - the default value of the shift

   Level: developer

@*/

PetscErrorCode STSetDefaultShift(ST st,PetscScalar defaultshift)

{

  PetscFunctionBegin;

  PetscValidHeaderSpecific(st,ST_CLASSID,1);

  PetscValidLogicalCollectiveScalar(st,defaultshift,2);

  st->defsigma = defaultshift;

  PetscFunctionReturn(0);

}

#undef __FUNCT__  

#define __FUNCT__ "STSetBalanceMatrix"

/*@

   STSetBalanceMatrix - Sets the diagonal matrix to be used for balancing.

   Collective on ST and Vec

   Input Parameters:

+  st - the spectral transformation context

-  D  - the diagonal matrix (represented as a vector)

   Notes:

   If this matrix is set, STApply will effectively apply D*OP*D^{-1}.

   Balancing is usually set via EPSSetBalance, but the advanced user may use

   this function to bypass the usual balancing methods.

   Level: developer

.seealso: EPSSetBalance(), STApply(), STGetBalanceMatrix()

@*/

PetscErrorCode STSetBalanceMatrix(ST st,Vec D)

{

  PetscErrorCode ierr;

  PetscFunctionBegin;

  PetscValidHeaderSpecific(st,ST_CLASSID,1);

  PetscValidHeaderSpecific(D,VEC_CLASSID,2);

  PetscCheckSameComm(st,1,D,2);

  ierr = PetscObjectReference((PetscObject)D);CHKERRQ(ierr);

  ierr = VecDestroy(&st->D); CHKERRQ(ierr);

  st->D = D;

  if (!st->wb) {

    ierr = VecDuplicate(st->D,&st->wb);CHKERRQ(ierr);

  }

  PetscFunctionReturn(0);

}

#undef __FUNCT__  

#define __FUNCT__ "STGetBalanceMatrix"

/*@

   STGetBalanceMatrix - Gets the balance matrix used by the spectral transformation.

   Not collective, but vector is shared by all processors that share the ST

   Input Parameter:

.  st - the spectral transformation context

   Output Parameter:

.  D  - the diagonal matrix (represented as a vector)

   Note:

   If the matrix was not set, a null pointer will be returned.

   Level: developer

.seealso: STSetBalanceMatrix()

@*/

PetscErrorCode STGetBalanceMatrix(ST st,Vec *D)

{

  PetscFunctionBegin;

  PetscValidHeaderSpecific(st,ST_CLASSID,1);

  PetscValidPointer(D,2);

  *D = st->D;

  PetscFunctionReturn(0);

}

#undef __FUNCT__  

#define __FUNCT__ "STSetOptionsPrefix"

/*@C

   STSetOptionsPrefix - Sets the prefix used for searching for all

   ST options in the database.

   Collective on ST

   Input Parameters:

+  st     - the spectral transformation context

-  prefix - the prefix string to prepend to all ST 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: STAppendOptionsPrefix(), STGetOptionsPrefix()

@*/

PetscErrorCode STSetOptionsPrefix(ST st,const char *prefix)

{

  PetscErrorCode ierr;

  PetscFunctionBegin;

  PetscValidHeaderSpecific(st,ST_CLASSID,1);

  ierr = PetscObjectSetOptionsPrefix((PetscObject)st,prefix);CHKERRQ(ierr);

  ierr = KSPSetOptionsPrefix(st->ksp,prefix);CHKERRQ(ierr);

  ierr = KSPAppendOptionsPrefix(st->ksp,"st_");CHKERRQ(ierr);

  PetscFunctionReturn(0);

}

#undef __FUNCT__  

#define __FUNCT__ "STAppendOptionsPrefix"

/*@C

   STAppendOptionsPrefix - Appends to the prefix used for searching for all

   ST options in the database.

   Collective on ST

   Input Parameters:

+  st     - the spectral transformation context

-  prefix - the prefix string to prepend to all ST 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: STSetOptionsPrefix(), STGetOptionsPrefix()

@*/

PetscErrorCode STAppendOptionsPrefix(ST st,const char *prefix)

{

  PetscErrorCode ierr;

  PetscFunctionBegin;

  PetscValidHeaderSpecific(st,ST_CLASSID,1);

  ierr = PetscObjectAppendOptionsPrefix((PetscObject)st,prefix);CHKERRQ(ierr);

  ierr = KSPSetOptionsPrefix(st->ksp,((PetscObject)st)->prefix);CHKERRQ(ierr);

  ierr = KSPAppendOptionsPrefix(st->ksp,"st_");CHKERRQ(ierr);

  PetscFunctionReturn(0);

}

#undef __FUNCT__  

#define __FUNCT__ "STGetOptionsPrefix"

/*@C

   STGetOptionsPrefix - Gets the prefix used for searching for all

   ST options in the database.

   Not Collective

   Input Parameters:

.  st - the spectral transformation 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: STSetOptionsPrefix(), STAppendOptionsPrefix()

@*/

PetscErrorCode STGetOptionsPrefix(ST st,const char *prefix[])

{

  PetscErrorCode ierr;

  PetscFunctionBegin;

  PetscValidHeaderSpecific(st,ST_CLASSID,1);

  PetscValidPointer(prefix,2);

  ierr = PetscObjectGetOptionsPrefix((PetscObject)st, prefix);CHKERRQ(ierr);

  PetscFunctionReturn(0);

}

#undef __FUNCT__  

#define __FUNCT__ "STView"

/*@C

   STView - Prints the ST data structure.

   Collective on ST

   Input Parameters:

+  ST - the ST context

-  viewer - optional visualization context

   Note:

   The available visualization contexts include

+     PETSC_VIEWER_STDOUT_SELF - standard output (default)

-     PETSC_VIEWER_STDOUT_WORLD - synchronized standard

         output where only the first processor opens

         the file.  All other processors send their

         data to the first processor to print.

   The user can open an alternative visualization contexts with

   PetscViewerASCIIOpen() (output to a specified file).

   Level: beginner

.seealso: EPSView(), PetscViewerASCIIOpen()

@*/

PetscErrorCode STView(ST st,PetscViewer viewer)

{

  PetscErrorCode    ierr;

  const STType      cstr;

  const char*       str;

  PetscBool         isascii,isstring;

  PetscViewerFormat format;

  PetscFunctionBegin;

  PetscValidHeaderSpecific(st,ST_CLASSID,1);

  if (!viewer) viewer = PETSC_VIEWER_STDOUT_(((PetscObject)st)->comm);

  PetscValidHeaderSpecific(viewer,PETSC_VIEWER_CLASSID,2);

  PetscCheckSameComm(st,1,viewer,2);

  ierr = PetscTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&isascii);CHKERRQ(ierr);

  ierr = PetscTypeCompare((PetscObject)viewer,PETSCVIEWERSTRING,&isstring);CHKERRQ(ierr);

  if (isascii) {

    ierr = PetscViewerGetFormat(viewer,&format);CHKERRQ(ierr);

    ierr = PetscObjectPrintClassNamePrefixType((PetscObject)st,viewer,"ST Object");CHKERRQ(ierr);

#if !defined(PETSC_USE_COMPLEX)

    ierr = PetscViewerASCIIPrintf(viewer,"  shift: %g\n",st->sigma);CHKERRQ(ierr);

#else

    ierr = PetscViewerASCIIPrintf(viewer,"  shift: %g+%g i\n",PetscRealPart(st->sigma),PetscImaginaryPart(st->sigma));CHKERRQ(ierr);

#endif

    switch (st->shift_matrix) {

    case ST_MATMODE_COPY:

      break;

    case ST_MATMODE_INPLACE:

      ierr = PetscViewerASCIIPrintf(viewer,"Shifting the matrix and unshifting at exit\n");CHKERRQ(ierr);

      break;

    case ST_MATMODE_SHELL:

      ierr = PetscViewerASCIIPrintf(viewer,"Using a shell matrix\n");CHKERRQ(ierr);

      break;

    }

    if (st->B && st->shift_matrix != ST_MATMODE_SHELL) {

      switch (st->str) {

        case SAME_NONZERO_PATTERN:      str = "same nonzero pattern";break;

        case DIFFERENT_NONZERO_PATTERN: str = "different nonzero pattern";break;

        case SUBSET_NONZERO_PATTERN:    str = "subset nonzero pattern";break;

        default:                        SETERRQ(((PetscObject)st)->comm,1,"Wrong structure flag");

      }

      ierr = PetscViewerASCIIPrintf(viewer,"Matrices A and B have %s\n",str);CHKERRQ(ierr);

    }

    if (st->ops->view) {

      ierr = PetscViewerASCIIPushTab(viewer);CHKERRQ(ierr);

      ierr = (*st->ops->view)(st,viewer);CHKERRQ(ierr);

      ierr = PetscViewerASCIIPopTab(viewer);CHKERRQ(ierr);

    }

  } else if (isstring) {

    ierr = STGetType(st,&cstr);CHKERRQ(ierr);

    ierr = PetscViewerStringSPrintf(viewer," %-7.7s",cstr);CHKERRQ(ierr);

    if (st->ops->view) {ierr = (*st->ops->view)(st,viewer);CHKERRQ(ierr);}

  } else {

    SETERRQ1(((PetscObject)st)->comm,1,"Viewer type %s not supported by ST",((PetscObject)viewer)->type_name);

  }

  PetscFunctionReturn(0);

}

#undef __FUNCT__  

#define __FUNCT__ "STView_Default"

PetscErrorCode STView_Default(ST st,PetscViewer viewer)

{

  PetscErrorCode ierr;

  PetscBool      isascii,isstring;

  PetscFunctionBegin;

  ierr = PetscTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&isascii);CHKERRQ(ierr);

  ierr = PetscTypeCompare((PetscObject)viewer,PETSCVIEWERSTRING,&isstring);CHKERRQ(ierr);

  if (isascii) {

    ierr = PetscViewerASCIIPushTab(viewer);CHKERRQ(ierr);

    ierr = PetscViewerASCIIPrintf(viewer,"Associated KSP object\n");CHKERRQ(ierr);

    ierr = PetscViewerASCIIPrintf(viewer,"------------------------------\n");CHKERRQ(ierr);

    ierr = KSPView(st->ksp,viewer);CHKERRQ(ierr);

    ierr = PetscViewerASCIIPrintf(viewer,"------------------------------\n");CHKERRQ(ierr);

    ierr = PetscViewerASCIIPopTab(viewer);CHKERRQ(ierr);

  } else if (isstring) {

    ierr = KSPView(st->ksp,viewer);CHKERRQ(ierr);

  }

  PetscFunctionReturn(0);

}

/*MC

   STRegisterDynamic - Adds a method to the spectral transformation package.

   Synopsis:

   STRegisterDynamic(char *name_solver,char *path,char *name_create,PetscErrorCode (*routine_create)(ST))

   Not collective

   Input Parameters:

+  name_solver - name of a new user-defined solver

.  path - path (either absolute or relative) the library containing this solver

.  name_create - name of routine to create method context

-  routine_create - routine to create method context

   Notes:

   STRegisterDynamic() may be called multiple times to add several user-defined spectral transformations.

   If dynamic libraries are used, then the fourth input argument (routine_create)

   is ignored.

   Sample usage:

.vb

   STRegisterDynamic("my_solver","/home/username/my_lib/lib/libO/solaris/mylib.a",

              "MySolverCreate",MySolverCreate);

.ve

   Then, your solver can be chosen with the procedural interface via

$     STSetType(st,"my_solver")

   or at runtime via the option

$     -st_type my_solver

   Level: advanced

   $PETSC_DIR, $PETSC_ARCH and $PETSC_LIB_DIR occuring in pathname will be replaced with appropriate values.

.seealso: STRegisterDestroy(), STRegisterAll()

M*/

#undef __FUNCT__  

#define __FUNCT__ "STRegister"

/*@C

   STRegister - See STRegisterDynamic()

   Level: advanced

@*/

PetscErrorCode STRegister(const char *sname,const char *path,const char *name,PetscErrorCode (*function)(ST))

{

  PetscErrorCode ierr;

  char           fullname[256];

  PetscFunctionBegin;

  ierr = PetscFListConcat(path,name,fullname);CHKERRQ(ierr);

  ierr = PetscFListAdd(&STList,sname,fullname,(void (*)(void))function);CHKERRQ(ierr);

  PetscFunctionReturn(0);

}

#undef __FUNCT__  

#define __FUNCT__ "STRegisterDestroy"

/*@

   STRegisterDestroy - Frees the list of ST methods that were

   registered by STRegisterDynamic().

   Not Collective

   Level: advanced

.seealso: STRegisterDynamic(), STRegisterAll()

@*/

PetscErrorCode STRegisterDestroy(void)

{

  PetscErrorCode ierr;

  PetscFunctionBegin;

  ierr = PetscFListDestroy(&STList);CHKERRQ(ierr);

  ierr = STRegisterAll(PETSC_NULL);CHKERRQ(ierr);

  PetscFunctionReturn(0);

}