Actual source code: mfnsetup.c

slepc-3.5.2 2014-10-10
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  1: /*
  2:       MFN routines related to problem setup.

  4:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  5:    SLEPc - Scalable Library for Eigenvalue Problem Computations
  6:    Copyright (c) 2002-2014, 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: advanced

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

 53:   if (mfn->setupcalled) return(0);
 54:   PetscLogEventBegin(MFN_SetUp,mfn,0,0,0);

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

 59:   /* Set default solver type (MFNSetFromOptions was not called) */
 60:   if (!((PetscObject)mfn)->type_name) {
 61:     MFNSetType(mfn,MFNKRYLOV);
 62:   }
 63:   if (!mfn->ds) { MFNGetDS(mfn,&mfn->ds); }
 64:   DSReset(mfn->ds);
 65:   if (!((PetscObject)mfn->rand)->type_name) {
 66:     PetscRandomSetFromOptions(mfn->rand);
 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:   /* Set default function */
 75:   if (!mfn->function) {
 76:     MFNSetFunction(mfn,SLEPC_FUNCTION_EXP);
 77:   }

 79:   /* call specific solver setup */
 80:   (*mfn->ops->setup)(mfn);

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

 85:   PetscLogEventEnd(MFN_SetUp,mfn,0,0,0);
 86:   mfn->setupcalled = 1;
 87:   return(0);
 88: }

 92: /*@
 93:    MFNSetOperator - Sets the matrix for which the matrix function is to be computed.

 95:    Collective on MFN and Mat

 97:    Input Parameters:
 98: +  mfn - the matrix function context
 99: -  A   - the problem matrix

101:    Notes:
102:    It must be called after MFNSetUp(). If it is called again after MFNSetUp() then
103:    the MFN object is reset.

105:    Level: beginner

107: .seealso: MFNSolve(), MFNSetUp(), MFNReset()
108: @*/
109: PetscErrorCode MFNSetOperator(MFN mfn,Mat A)
110: {
112:   PetscInt       m,n;


119:   MatGetSize(A,&m,&n);
120:   if (m!=n) SETERRQ(PetscObjectComm((PetscObject)mfn),PETSC_ERR_ARG_WRONG,"A is a non-square matrix");
121:   if (mfn->setupcalled) { MFNReset(mfn); }
122:   PetscObjectReference((PetscObject)A);
123:   MatDestroy(&mfn->A);
124:   mfn->A = A;
125:   return(0);
126: }

130: /*@
131:    MFNGetOperator - Gets the matrix associated with the MFN object.

133:    Collective on MFN and Mat

135:    Input Parameter:
136: .  mfn - the MFN context

138:    Output Parameters:
139: .  A  - the matrix for which the matrix function is to be computed

141:    Level: intermediate

143: .seealso: MFNSolve(), MFNSetOperator()
144: @*/
145: PetscErrorCode MFNGetOperator(MFN mfn,Mat *A)
146: {
150:   *A = mfn->A;
151:   return(0);
152: }

156: /*@
157:    MFNAllocateSolution - Allocate memory storage for common variables such
158:    as the basis vectors.

160:    Collective on MFN

162:    Input Parameters:
163: +  mfn   - eigensolver context
164: -  extra - number of additional positions, used for methods that require a
165:            working basis slightly larger than ncv

167:    Developers Note:
168:    This is PETSC_EXTERN because it may be required by user plugin MFN
169:    implementations.

171:    Level: developer
172: @*/
173: PetscErrorCode MFNAllocateSolution(MFN mfn,PetscInt extra)
174: {
176:   PetscInt       oldsize,requested;
177:   Vec            t;

180:   requested = mfn->ncv + extra;

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

185:   /* allocate basis vectors */
186:   if (!mfn->V) { MFNGetBV(mfn,&mfn->V); }
187:   if (!oldsize) {
188:     if (!((PetscObject)(mfn->V))->type_name) {
189:       BVSetType(mfn->V,BVSVEC);
190:     }
191:     MatGetVecs(mfn->A,&t,NULL);
192:     BVSetSizesFromVec(mfn->V,t,requested);
193:     VecDestroy(&t);
194:   } else {
195:     BVResize(mfn->V,requested,PETSC_FALSE);
196:   }
197:   return(0);
198: }