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/*

     The basic EPS routines, Create, View, etc. are here.

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

   SLEPc - Scalable Library for Eigenvalue Problem Computations

   Copyright (c) 2002-2009, 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/epsimpl.h"      /*I "slepceps.h" I*/

PetscFList EPSList = 0;

PetscCookie EPS_COOKIE = 0;

PetscLogEvent EPS_SetUp = 0, EPS_Solve = 0, EPS_Dense = 0;

static PetscTruth EPSPackageInitialized = PETSC_FALSE;

#undef __FUNCT__  

#define __FUNCT__ "EPSFinalizePackage"

/*@C

  EPSFinalizePackage - This function destroys everything in the Slepc interface to the EPS package. It is

  called from SlepcFinalize().

  Level: developer

.seealso: SlepcFinalize()

@*/

PetscErrorCode EPSFinalizePackage(void)

{

  PetscFunctionBegin;

  EPSPackageInitialized = PETSC_FALSE;

  EPSList               = 0;

  PetscFunctionReturn(0);

}

#undef __FUNCT__  

#define __FUNCT__ "EPSInitializePackage"

/*@C

  EPSInitializePackage - This function initializes everything in the EPS package. It is called

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

  when using static libraries.

  Input Parameter:

  path - The dynamic library path, or PETSC_NULL

  Level: developer

.seealso: SlepcInitialize()

@*/

PetscErrorCode EPSInitializePackage(char *path) {

  char              logList[256];

  char             *className;

  PetscTruth        opt;

  PetscErrorCode ierr;

  PetscFunctionBegin;

  if (EPSPackageInitialized) PetscFunctionReturn(0);

  EPSPackageInitialized = PETSC_TRUE;

  /* Register Classes */

  ierr = PetscCookieRegister("Eigenproblem Solver",&EPS_COOKIE);CHKERRQ(ierr);

  /* Register Constructors */

  ierr = EPSRegisterAll(path);CHKERRQ(ierr);

  /* Register Events */

  ierr = PetscLogEventRegister("EPSSetUp",EPS_COOKIE,&EPS_SetUp);CHKERRQ(ierr);

  ierr = PetscLogEventRegister("EPSSolve",EPS_COOKIE,&EPS_Solve);CHKERRQ(ierr);

  ierr = PetscLogEventRegister("EPSDense",EPS_COOKIE,&EPS_Dense); CHKERRQ(ierr);

  /* Process info exclusions */

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

  if (opt) {

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

    if (className) {

      ierr = PetscInfoDeactivateClass(EPS_COOKIE);CHKERRQ(ierr);

    }

  }

  /* Process summary exclusions */

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

  if (opt) {

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

    if (className) {

      ierr = PetscLogEventDeactivateClass(EPS_COOKIE);CHKERRQ(ierr);

    }

  }

  ierr = PetscRegisterFinalize(EPSFinalizePackage);CHKERRQ(ierr);

  PetscFunctionReturn(0);

}

#undef __FUNCT__  

#define __FUNCT__ "EPSView"

/*@C

   EPSView - Prints the EPS data structure.

   Collective on EPS

   Input Parameters:

+  eps - the eigenproblem solver context

-  viewer - optional visualization context

   Options Database Key:

.  -eps_view -  Calls EPSView() at end of EPSSolve()

   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 context with

   PetscViewerASCIIOpen() - output to a specified file.

   Level: beginner

.seealso: STView(), PetscViewerASCIIOpen()

@*/

PetscErrorCode EPSView(EPS eps,PetscViewer viewer)

{

  PetscErrorCode ierr;

  const char     *type,*extr,*bal;

  PetscTruth     isascii;

  PetscFunctionBegin;

  PetscValidHeaderSpecific(eps,EPS_COOKIE,1);

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

  PetscValidHeaderSpecific(viewer,PETSC_VIEWER_COOKIE,2);

  PetscCheckSameComm(eps,1,viewer,2);

#if defined(PETSC_USE_COMPLEX)

#define HERM "hermitian"

#else

#define HERM "symmetric"

#endif

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

  if (isascii) {

    ierr = PetscViewerASCIIPrintf(viewer,"EPS Object:\n");CHKERRQ(ierr);

    switch (eps->problem_type) {

      case EPS_HEP:   type = HERM " eigenvalue problem"; break;

      case EPS_GHEP:  type = "generalized " HERM " eigenvalue problem"; break;

      case EPS_NHEP:  type = "non-" HERM " eigenvalue problem"; break;

      case EPS_GNHEP: type = "generalized non-" HERM " eigenvalue problem"; break;

      case EPS_PGNHEP: type = "generalized non-" HERM " eigenvalue problem with " HERM " positive definite B"; break;

      case EPS_GHIEP: type = "generalized " HERM "-indefinite eigenvalue problem"; break;

      case 0:         type = "not yet set"; break;

      default: SETERRQ(1,"Wrong value of eps->problem_type");

    }

    ierr = PetscViewerASCIIPrintf(viewer,"  problem type: %s\n",type);CHKERRQ(ierr);

    ierr = EPSGetType(eps,&type);CHKERRQ(ierr);

    if (type) {

      ierr = PetscViewerASCIIPrintf(viewer,"  method: %s\n",type);CHKERRQ(ierr);

    } else {

      ierr = PetscViewerASCIIPrintf(viewer,"  method: not yet set\n");CHKERRQ(ierr);

    }

    if (eps->ops->view) {

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

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

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

    }

    if (eps->extraction) {

      switch (eps->extraction) {

        case EPS_RITZ:             extr = "Rayleigh-Ritz"; break;

        case EPS_HARMONIC:         extr = "harmonic Ritz"; break;

        case EPS_HARMONIC_RELATIVE:extr = "relative harmonic Ritz"; break;

        case EPS_HARMONIC_RIGHT:   extr = "right harmonic Ritz"; break;

        case EPS_HARMONIC_LARGEST: extr = "largest harmonic Ritz"; break;

        case EPS_REFINED:          extr = "refined Ritz"; break;

        case EPS_REFINED_HARMONIC: extr = "refined harmonic Ritz"; break;

        default: SETERRQ(1,"Wrong value of eps->extraction");

      }

      ierr = PetscViewerASCIIPrintf(viewer,"  extraction type: %s\n",extr);CHKERRQ(ierr);

    }

    if (eps->balance && !eps->ishermitian && eps->balance!=EPS_BALANCE_NONE) {

      switch (eps->balance) {

        case EPS_BALANCE_ONESIDE:   bal = "one-sided Krylov"; break;

        case EPS_BALANCE_TWOSIDE:   bal = "two-sided Krylov"; break;

        case EPS_BALANCE_USER:      bal = "user-defined matrix"; break;

        default: SETERRQ(1,"Wrong value of eps->balance");

      }

      ierr = PetscViewerASCIIPrintf(viewer,"  balancing enabled: %s",bal);CHKERRQ(ierr);

      if (eps->balance==EPS_BALANCE_ONESIDE || eps->balance==EPS_BALANCE_TWOSIDE) {

        ierr = PetscViewerASCIIPrintf(viewer,", with its=%d",eps->balance_its);CHKERRQ(ierr);

      }

      if (eps->balance==EPS_BALANCE_TWOSIDE && eps->balance_cutoff!=0.0) {

        ierr = PetscViewerASCIIPrintf(viewer," and cutoff=%g",eps->balance_cutoff);CHKERRQ(ierr);

      }

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

    }

    ierr = PetscViewerASCIIPrintf(viewer,"  selected portion of the spectrum: ");CHKERRQ(ierr);

    if (!eps->which) {

      ierr = PetscViewerASCIIPrintf(viewer,"not yet set\n");CHKERRQ(ierr);

    } else switch (eps->which) {

      case EPS_WHICH_USER:

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

        break;

      case EPS_TARGET_MAGNITUDE:

#if !defined(PETSC_USE_COMPLEX)

        ierr = PetscViewerASCIIPrintf(viewer,"closest to target: %g (in magnitude)\n",eps->target);CHKERRQ(ierr);

#else

        ierr = PetscViewerASCIIPrintf(viewer,"closest to target: %g+%g i (in magnitude)\n",PetscRealPart(eps->target),PetscImaginaryPart(eps->target));CHKERRQ(ierr);

#endif

        break;

      case EPS_TARGET_REAL:

#if !defined(PETSC_USE_COMPLEX)

        ierr = PetscViewerASCIIPrintf(viewer,"closest to target: %g (along the real axis)\n",eps->target);CHKERRQ(ierr);

#else

        ierr = PetscViewerASCIIPrintf(viewer,"closest to target: %g+%g i (along the real axis)\n",PetscRealPart(eps->target),PetscImaginaryPart(eps->target));CHKERRQ(ierr);

#endif

        break;

#if defined(PETSC_USE_COMPLEX)

      case EPS_TARGET_IMAGINARY:

        ierr = PetscViewerASCIIPrintf(viewer,"closest to target: %g+%g i (along the imaginary axis)\n",PetscRealPart(eps->target),PetscImaginaryPart(eps->target));CHKERRQ(ierr);

        break;

#endif

      case EPS_LARGEST_MAGNITUDE:

        ierr = PetscViewerASCIIPrintf(viewer,"largest eigenvalues in magnitude\n");CHKERRQ(ierr);

        break;

      case EPS_SMALLEST_MAGNITUDE:

        ierr = PetscViewerASCIIPrintf(viewer,"smallest eigenvalues in magnitude\n");CHKERRQ(ierr);

        break;

      case EPS_LARGEST_REAL:

        ierr = PetscViewerASCIIPrintf(viewer,"largest real parts\n");CHKERRQ(ierr);

        break;

      case EPS_SMALLEST_REAL:

        ierr = PetscViewerASCIIPrintf(viewer,"smallest real parts\n");CHKERRQ(ierr);

        break;

      case EPS_LARGEST_IMAGINARY:

        ierr = PetscViewerASCIIPrintf(viewer,"largest imaginary parts\n");CHKERRQ(ierr);

        break;

      case EPS_SMALLEST_IMAGINARY:

        ierr = PetscViewerASCIIPrintf(viewer,"smallest imaginary parts\n");CHKERRQ(ierr);

        break;

      default: SETERRQ(1,"Wrong value of eps->which");

    }    

    if (eps->leftvecs) {

      ierr = PetscViewerASCIIPrintf(viewer,"  computing left eigenvectors also\n");CHKERRQ(ierr);

    }

    if (eps->trueres) {

      ierr = PetscViewerASCIIPrintf(viewer,"  computing true residuals explicitly\n");CHKERRQ(ierr);

    }

    if (eps->trackall) {

      ierr = PetscViewerASCIIPrintf(viewer,"  computing all residuals (for tracking convergence)\n");CHKERRQ(ierr);

    }

    ierr = PetscViewerASCIIPrintf(viewer,"  number of eigenvalues (nev): %d\n",eps->nev);CHKERRQ(ierr);

    ierr = PetscViewerASCIIPrintf(viewer,"  number of column vectors (ncv): %d\n",eps->ncv);CHKERRQ(ierr);

    ierr = PetscViewerASCIIPrintf(viewer,"  maximum dimension of projected problem (mpd): %d\n",eps->mpd);CHKERRQ(ierr);

    ierr = PetscViewerASCIIPrintf(viewer,"  maximum number of iterations: %d\n", eps->max_it);

    ierr = PetscViewerASCIIPrintf(viewer,"  tolerance: %g\n",eps->tol);CHKERRQ(ierr);

    switch(eps->conv) {

    case EPS_CONV_ABS:

      ierr = PetscViewerASCIIPrintf(viewer,"  absolute error convergence test\n");CHKERRQ(ierr);break;

    case EPS_CONV_EIG:

      ierr = PetscViewerASCIIPrintf(viewer,"  eigenvalue relative error convergence test\n");CHKERRQ(ierr);break;

    case EPS_CONV_NORM:

      ierr = PetscViewerASCIIPrintf(viewer,"  eigenvalue and matrix norm relative error convergence test\n");CHKERRQ(ierr);break;

    default:

      ierr = PetscViewerASCIIPrintf(viewer,"  user defined convergence test\n");CHKERRQ(ierr);break;

    }

    if (eps->nini!=0) {

      ierr = PetscViewerASCIIPrintf(viewer,"  dimension of user-provided initial space: %d\n",PetscAbs(eps->nini));CHKERRQ(ierr);

    }

    if (eps->ninil!=0) {

      ierr = PetscViewerASCIIPrintf(viewer,"  dimension of user-provided initial left space: %d\n",PetscAbs(eps->ninil));CHKERRQ(ierr);

    }

    if (eps->nds>0) {

      ierr = PetscViewerASCIIPrintf(viewer,"  dimension of user-provided deflation space: %d\n",eps->nds);CHKERRQ(ierr);

    }

    ierr = PetscViewerASCIIPrintf(viewer,"  estimates of matrix norms (%s): norm(A)=%g",eps->adaptive?"adaptive":"constant",eps->nrma);CHKERRQ(ierr);

    if (eps->isgeneralized) {

      ierr = PetscViewerASCIIPrintf(viewer,", norm(B)=%g",eps->nrmb);CHKERRQ(ierr);

    }

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

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

    ierr = IPView(eps->ip,viewer); CHKERRQ(ierr);

    ierr = STView(eps->OP,viewer); CHKERRQ(ierr);

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

  } else {

    if (eps->ops->view) {

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

    }

    ierr = STView(eps->OP,viewer); CHKERRQ(ierr);

  }

  PetscFunctionReturn(0);

}

#undef __FUNCT__  

#define __FUNCT__ "EPSCreate"

/*@C

   EPSCreate - Creates the default EPS context.

   Collective on MPI_Comm

   Input Parameter:

.  comm - MPI communicator

   Output Parameter:

.  eps - location to put the EPS context

   Note:

   The default EPS type is EPSKRYLOVSCHUR

   Level: beginner

.seealso: EPSSetUp(), EPSSolve(), EPSDestroy(), EPS

@*/

PetscErrorCode EPSCreate(MPI_Comm comm,EPS *outeps)

{

  PetscErrorCode ierr;

  EPS            eps;

  PetscFunctionBegin;

  PetscValidPointer(outeps,2);

  *outeps = 0;

  ierr = PetscHeaderCreate(eps,_p_EPS,struct _EPSOps,EPS_COOKIE,-1,"EPS",comm,EPSDestroy,EPSView);CHKERRQ(ierr);

  *outeps = eps;

  ierr = PetscMemzero(eps->ops,sizeof(struct _EPSOps));CHKERRQ(ierr);

  eps->max_it          = 0;

  eps->nev             = 1;

  eps->ncv             = 0;

  eps->mpd             = 0;

  eps->allocated_ncv   = 0;

  eps->nini            = 0;

  eps->ninil           = 0;

  eps->nds             = 0;

  eps->tol             = 1e-7;

  eps->conv_func       = EPSEigRelativeConverged;

  eps->conv_ctx        = PETSC_NULL;

  eps->which           = (EPSWhich)0;

  eps->which_func      = PETSC_NULL;

  eps->which_ctx       = PETSC_NULL;

  eps->leftvecs        = PETSC_FALSE;

  eps->trueres         = PETSC_FALSE;

  eps->trackall        = PETSC_FALSE;

  eps->target          = 0.0;

  eps->evecsavailable  = PETSC_FALSE;

  eps->problem_type    = (EPSProblemType)0;

  eps->extraction      = (EPSExtraction)0;

  eps->balance         = (EPSBalance)0;

  eps->balance_its     = 5;

  eps->balance_cutoff  = 1e-8;

  eps->nrma            = 1.0;

  eps->nrmb            = 1.0;

  eps->adaptive        = PETSC_FALSE;

  eps->V               = 0;

  eps->W               = 0;

  eps->T               = 0;

  eps->DS              = 0;

  eps->IS              = 0;

  eps->ISL             = 0;

  eps->ds_ortho        = PETSC_FALSE;

  eps->eigr            = 0;

  eps->eigi            = 0;

  eps->errest          = 0;

  eps->errest_left     = 0;

  eps->OP              = 0;

  eps->ip              = 0;

  eps->data            = 0;

  eps->nconv           = 0;

  eps->its             = 0;

  eps->perm            = PETSC_NULL;

  eps->nwork           = 0;

  eps->work            = 0;

  eps->isgeneralized   = PETSC_FALSE;

  eps->ishermitian     = PETSC_FALSE;

  eps->ispositive      = PETSC_FALSE;

  eps->setupcalled     = 0;

  eps->reason          = EPS_CONVERGED_ITERATING;

  eps->numbermonitors  = 0;

  ierr = STCreate(comm,&eps->OP); CHKERRQ(ierr);

  PetscLogObjectParent(eps,eps->OP);

  ierr = IPCreate(comm,&eps->ip); CHKERRQ(ierr);

  ierr = IPSetOptionsPrefix(eps->ip,((PetscObject)eps)->prefix);

  ierr = IPAppendOptionsPrefix(eps->ip,"eps_");

  PetscLogObjectParent(eps,eps->ip);

  ierr = PetscPublishAll(eps);CHKERRQ(ierr);

  PetscFunctionReturn(0);

}

#undef __FUNCT__  

#define __FUNCT__ "EPSSetType"

/*@C

   EPSSetType - Selects the particular solver to be used in the EPS object.

   Collective on EPS

   Input Parameters:

+  eps      - the eigensolver context

-  type     - a known method

   Options Database Key:

.  -eps_type <method> - Sets the method; use -help for a list

    of available methods

   Notes:  

   See "slepc/include/slepceps.h" for available methods. The default

   is EPSKRYLOVSCHUR.

   Normally, it is best to use the EPSSetFromOptions() command and

   then set the EPS type from the options database rather than by using

   this routine.  Using the options database provides the user with

   maximum flexibility in evaluating the different available methods.

   The EPSSetType() routine is provided for those situations where it

   is necessary to set the iterative solver independently of the command

   line or options database.

   Level: intermediate

.seealso: STSetType(), EPSType

@*/

PetscErrorCode EPSSetType(EPS eps,const EPSType type)

{

  PetscErrorCode ierr,(*r)(EPS);

  PetscTruth match;

  PetscFunctionBegin;

  PetscValidHeaderSpecific(eps,EPS_COOKIE,1);

  PetscValidCharPointer(type,2);

  ierr = PetscTypeCompare((PetscObject)eps,type,&match);CHKERRQ(ierr);

  if (match) PetscFunctionReturn(0);

  if (eps->data) {

    /* destroy the old private EPS context */

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

    eps->data = 0;

  }

  ierr = PetscFListFind(EPSList,((PetscObject)eps)->comm,type,(void (**)(void)) &r);CHKERRQ(ierr);

  if (!r) SETERRQ1(1,"Unknown EPS type given: %s",type);

  eps->setupcalled = 0;

  ierr = PetscMemzero(eps->ops,sizeof(struct _EPSOps));CHKERRQ(ierr);

  ierr = (*r)(eps); CHKERRQ(ierr);

  ierr = PetscObjectChangeTypeName((PetscObject)eps,type);CHKERRQ(ierr);

  PetscFunctionReturn(0);

}

#undef __FUNCT__  

#define __FUNCT__ "EPSGetType"

/*@C

   EPSGetType - Gets the EPS type as a string from the EPS object.

   Not Collective

   Input Parameter:

.  eps - the eigensolver context

   Output Parameter:

.  name - name of EPS method

   Level: intermediate

.seealso: EPSSetType()

@*/

PetscErrorCode EPSGetType(EPS eps,const EPSType *type)

{

  PetscFunctionBegin;

  PetscValidHeaderSpecific(eps,EPS_COOKIE,1);

  PetscValidPointer(type,2);

  *type = ((PetscObject)eps)->type_name;

  PetscFunctionReturn(0);

}

/*MC

   EPSRegisterDynamic - Adds a method to the eigenproblem solver package.

   Synopsis:

   EPSRegisterDynamic(char *name_solver,char *path,char *name_create,PetscErrorCode (*routine_create)(EPS))

   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 the solver context

-  routine_create - routine to create the solver context

   Notes:

   EPSRegisterDynamic() may be called multiple times to add several user-defined solvers.

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

   is ignored.

   Sample usage:

.vb

   EPSRegisterDynamic("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

$     EPSSetType(eps,"my_solver")

   or at runtime via the option

$     -eps_type my_solver

   Level: advanced

   Environmental variables such as ${PETSC_ARCH}, ${PETSC_DIR}, ${PETSC_LIB_DIR},

   and others of the form ${any_environmental_variable} occuring in pathname will be

   replaced with appropriate values.

.seealso: EPSRegisterDestroy(), EPSRegisterAll()

M*/

#undef __FUNCT__  

#define __FUNCT__ "EPSRegister"

/*@C

  EPSRegister - See EPSRegisterDynamic()

  Level: advanced

@*/

PetscErrorCode EPSRegister(const char *sname,const char *path,const char *name,PetscErrorCode (*function)(EPS))

{

  PetscErrorCode ierr;

  char           fullname[256];

  PetscFunctionBegin;

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

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

  PetscFunctionReturn(0);

}

#undef __FUNCT__  

#define __FUNCT__ "EPSRegisterDestroy"

/*@

   EPSRegisterDestroy - Frees the list of EPS methods that were

   registered by EPSRegisterDynamic().

   Not Collective

   Level: advanced

.seealso: EPSRegisterDynamic(), EPSRegisterAll()

@*/

PetscErrorCode EPSRegisterDestroy(void)

{

  PetscErrorCode ierr;

  PetscFunctionBegin;

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

  ierr = EPSRegisterAll(PETSC_NULL);CHKERRQ(ierr);

  PetscFunctionReturn(0);

}

#undef __FUNCT__  

#define __FUNCT__ "EPSDestroy"

/*@

   EPSDestroy - Destroys the EPS context.

   Collective on EPS

   Input Parameter:

.  eps - eigensolver context obtained from EPSCreate()

   Level: beginner

.seealso: EPSCreate(), EPSSetUp(), EPSSolve()

@*/

PetscErrorCode EPSDestroy(EPS eps)

{

  PetscErrorCode ierr;

  PetscFunctionBegin;

  PetscValidHeaderSpecific(eps,EPS_COOKIE,1);

  if (--((PetscObject)eps)->refct > 0) PetscFunctionReturn(0);

  /* if memory was published with AMS then destroy it */

  ierr = PetscObjectDepublish(eps);CHKERRQ(ierr);

  ierr = STDestroy(eps->OP);CHKERRQ(ierr);

  ierr = IPDestroy(eps->ip);CHKERRQ(ierr);

  if (eps->ops->destroy) {

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

  }

  ierr = PetscFree(eps->T);CHKERRQ(ierr);

  ierr = PetscFree(eps->Tl);CHKERRQ(ierr);

  ierr = PetscFree(eps->perm);CHKERRQ(ierr);

  ierr = PetscRandomDestroy(eps->rand);CHKERRQ(ierr);

  if (eps->D) {

    ierr = VecDestroy(eps->D);CHKERRQ(ierr);

  }

  ierr = EPSRemoveDeflationSpace(eps);CHKERRQ(ierr);

  ierr = EPSMonitorCancel(eps);CHKERRQ(ierr);

  ierr = PetscHeaderDestroy(eps);CHKERRQ(ierr);

  PetscFunctionReturn(0);

}

#undef __FUNCT__  

#define __FUNCT__ "EPSSetTarget"

/*@

   EPSSetTarget - Sets the value of the target.

   Collective on EPS

   Input Parameters:

+  eps    - eigensolver context

-  target - the value of the target

   Notes:

   The target is a scalar value used to determine the portion of the spectrum

   of interest. It is used in combination with EPSSetWhichEigenpairs().

   Level: beginner

.seealso: EPSGetTarget(), EPSSetWhichEigenpairs()

@*/

PetscErrorCode EPSSetTarget(EPS eps,PetscScalar target)

{

  PetscErrorCode ierr;

  PetscFunctionBegin;

  PetscValidHeaderSpecific(eps,EPS_COOKIE,1);

  eps->target = target;

  ierr = STSetDefaultShift(eps->OP,target);CHKERRQ(ierr);

  PetscFunctionReturn(0);

}

#undef __FUNCT__  

#define __FUNCT__ "EPSGetTarget"

/*@

   EPSGetTarget - Gets the value of the target.

   Not collective

   Input Parameter:

.  eps - eigensolver context

   Output Parameter:

.  target - the value of the target

   Level: beginner

   Note:

   If the target was not set by the user, then zero is returned.

.seealso: EPSSetTarget()

@*/

PetscErrorCode EPSGetTarget(EPS eps,PetscScalar* target)

{

  PetscFunctionBegin;

  PetscValidHeaderSpecific(eps,EPS_COOKIE,1);

  if (target) {

    *target = eps->target;

  }

  PetscFunctionReturn(0);

}

#undef __FUNCT__  

#define __FUNCT__ "EPSSetST"

/*@

   EPSSetST - Associates a spectral transformation object to the

   eigensolver.

   Collective on EPS and ST

   Input Parameters:

+  eps - eigensolver context obtained from EPSCreate()

-  st   - the spectral transformation object

   Note:

   Use EPSGetST() to retrieve the spectral transformation context (for example,

   to free it at the end of the computations).

   Level: advanced

.seealso: EPSGetST()

@*/

PetscErrorCode EPSSetST(EPS eps,ST st)

{

  PetscErrorCode ierr;

  PetscFunctionBegin;

  PetscValidHeaderSpecific(eps,EPS_COOKIE,1);

  PetscValidHeaderSpecific(st,ST_COOKIE,2);

  PetscCheckSameComm(eps,1,st,2);

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

  ierr = STDestroy(eps->OP); CHKERRQ(ierr);

  eps->OP = st;

  PetscFunctionReturn(0);