Date: 2016-09-29T11:13:11+00:00

Actual source code: mfnsetup.c
slepc-3.7.3 2016-09-29
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      1: /*
      2:       MFN routines related to problem setup.

      4:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
      5:    SLEPc - Scalable Library for Eigenvalue Problem Computations
      6:    Copyright (c) 2002-2016, Universitat Politecnica de Valencia, Spain

      8:    This file is part of SLEPc.

     10:    SLEPc is free software: you can redistribute it and/or modify it under  the
     11:    terms of version 3 of the GNU Lesser General Public License as published by
     12:    the Free Software Foundation.

     14:    SLEPc  is  distributed in the hope that it will be useful, but WITHOUT  ANY
     15:    WARRANTY;  without even the implied warranty of MERCHANTABILITY or  FITNESS
     16:    FOR  A  PARTICULAR PURPOSE. See the GNU Lesser General Public  License  for
     17:    more details.

     19:    You  should have received a copy of the GNU Lesser General  Public  License
     20:    along with SLEPc. If not, see <http://www.gnu.org/licenses/>.
     21:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     22: */

     24: #include <slepc/private/mfnimpl.h>       /*I "slepcmfn.h" I*/

     28: /*@
     29:    MFNSetUp - Sets up all the internal data structures necessary for the
     30:    execution of the matrix function solver.

     32:    Collective on MFN

     34:    Input Parameter:
     35: .  mfn   - matrix function context

     37:    Notes:
     38:    This function need not be called explicitly in most cases, since MFNSolve()
     39:    calls it. It can be useful when one wants to measure the set-up time
     40:    separately from the solve time.

     42:    Level: developer

     44: .seealso: MFNCreate(), MFNSolve(), MFNDestroy()
     45: @*/
     46: PetscErrorCode MFNSetUp(MFN mfn)
     47: {
     49:   PetscInt       N;

     54:   /* reset the convergence flag from the previous solves */
     55:   mfn->reason = MFN_CONVERGED_ITERATING;

     57:   if (mfn->setupcalled) return(0);
     58:   PetscLogEventBegin(MFN_SetUp,mfn,0,0,0);

     60:   /* Set default solver type (MFNSetFromOptions was not called) */
     61:   if (!((PetscObject)mfn)->type_name) {
     62:     MFNSetType(mfn,MFNKRYLOV);
     63:   }
     64:   if (!mfn->fn) { MFNGetFN(mfn,&mfn->fn); }
     65:   if (!((PetscObject)mfn->fn)->type_name) {
     66:     FNSetFromOptions(mfn->fn);
     67:   }

     69:   /* Check problem dimensions */
     70:   if (!mfn->A) SETERRQ(PetscObjectComm((PetscObject)mfn),PETSC_ERR_ARG_WRONGSTATE,"MFNSetOperator must be called first");
     71:   MatGetSize(mfn->A,&N,NULL);
     72:   if (mfn->ncv > N) mfn->ncv = N;

     74:   /* call specific solver setup */
     75:   (*mfn->ops->setup)(mfn);

     77:   /* set tolerance if not yet set */
     78:   if (mfn->tol==PETSC_DEFAULT) mfn->tol = SLEPC_DEFAULT_TOL;

     80:   PetscLogEventEnd(MFN_SetUp,mfn,0,0,0);
     81:   mfn->setupcalled = 1;
     82:   return(0);
     83: }

     87: /*@
     88:    MFNSetOperator - Sets the matrix for which the matrix function is to be computed.

     90:    Collective on MFN and Mat

     92:    Input Parameters:
     93: +  mfn - the matrix function context
     94: -  A   - the problem matrix

     96:    Notes:
     97:    It must be called before MFNSetUp(). If it is called again after MFNSetUp() then
     98:    the MFN object is reset.

    100:    Level: beginner

    102: .seealso: MFNSolve(), MFNSetUp(), MFNReset()
    103: @*/
    104: PetscErrorCode MFNSetOperator(MFN mfn,Mat A)
    105: {
    107:   PetscInt       m,n;

    114:   MatGetSize(A,&m,&n);
    115:   if (m!=n) SETERRQ(PetscObjectComm((PetscObject)mfn),PETSC_ERR_ARG_WRONG,"A is a non-square matrix");
    116:   if (mfn->setupcalled) { MFNReset(mfn); }
    117:   PetscObjectReference((PetscObject)A);
    118:   MatDestroy(&mfn->A);
    119:   mfn->A = A;
    120:   return(0);
    121: }

    125: /*@
    126:    MFNGetOperator - Gets the matrix associated with the MFN object.

    128:    Collective on MFN and Mat

    130:    Input Parameter:
    131: .  mfn - the MFN context

    133:    Output Parameters:
    134: .  A  - the matrix for which the matrix function is to be computed

    136:    Level: intermediate

    138: .seealso: MFNSolve(), MFNSetOperator()
    139: @*/
    140: PetscErrorCode MFNGetOperator(MFN mfn,Mat *A)
    141: {
    145:   *A = mfn->A;
    146:   return(0);
    147: }

    151: /*@
    152:    MFNAllocateSolution - Allocate memory storage for common variables such
    153:    as the basis vectors.

    155:    Collective on MFN

    157:    Input Parameters:
    158: +  mfn   - eigensolver context
    159: -  extra - number of additional positions, used for methods that require a
    160:            working basis slightly larger than ncv

    162:    Developers Note:
    163:    This is PETSC_EXTERN because it may be required by user plugin MFN
    164:    implementations.

    166:    Level: developer
    167: @*/
    168: PetscErrorCode MFNAllocateSolution(MFN mfn,PetscInt extra)
    169: {
    171:   PetscInt       oldsize,requested;
    172:   Vec            t;

    175:   requested = mfn->ncv + extra;

    177:   /* oldsize is zero if this is the first time setup is called */
    178:   BVGetSizes(mfn->V,NULL,NULL,&oldsize);

    180:   /* allocate basis vectors */
    181:   if (!mfn->V) { MFNGetBV(mfn,&mfn->V); }
    182:   if (!oldsize) {
    183:     if (!((PetscObject)(mfn->V))->type_name) {
    184:       BVSetType(mfn->V,BVSVEC);
    185:     }
    186:     MatCreateVecs(mfn->A,&t,NULL);
    187:     BVSetSizesFromVec(mfn->V,t,requested);
    188:     VecDestroy(&t);
    189:   } else {
    190:     BVResize(mfn->V,requested,PETSC_FALSE);
    191:   }
    192:   return(0);
    193: }