Actual source code: trlan.c

  1: /*
  2:    This file implements a wrapper to the TRLAN package

  4:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  5:    SLEPc - Scalable Library for Eigenvalue Problem Computations
  6:    Copyright (c) 2002-2013, 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/epsimpl.h>          /*I "slepceps.h" I*/
 25: #include <../src/eps/impls/external/trlan/trlanp.h>

 27: PetscErrorCode EPSSolve_TRLAN(EPS);

 29: /* Nasty global variable to access EPS data from TRLan_ */
 30: static EPS globaleps;

 34: PetscErrorCode EPSSetUp_TRLAN(EPS eps)
 35: {
 37:   EPS_TRLAN      *tr = (EPS_TRLAN*)eps->data;

 40:   PetscBLASIntCast(PetscMax(7,eps->nev+PetscMin(eps->nev,6)),&tr->maxlan);
 41:   if (eps->ncv) {
 42:     if (eps->ncv<eps->nev) SETERRQ(PetscObjectComm((PetscObject)eps),1,"The value of ncv must be at least nev");
 43:   } else eps->ncv = tr->maxlan;
 44:   if (eps->mpd) { PetscInfo(eps,"Warning: parameter mpd ignored\n"); }
 45:   if (!eps->max_it) eps->max_it = PetscMax(1000,eps->n);

 47:   if (!eps->ishermitian) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"Requested method is only available for Hermitian problems");

 49:   if (eps->isgeneralized) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"Requested method is not available for generalized problems");

 51:   if (!eps->which) eps->which = EPS_LARGEST_REAL;
 52:   if (eps->which!=EPS_LARGEST_REAL && eps->which!=EPS_SMALLEST_REAL && eps->which!=EPS_TARGET_REAL) SETERRQ(PetscObjectComm((PetscObject)eps),1,"Wrong value of eps->which");
 53:   if (eps->arbitrary) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"Arbitrary selection of eigenpairs not supported in this solver");

 55:   tr->restart = 0;
 56:   if (tr->maxlan+1-eps->ncv<=0) {
 57:     PetscBLASIntCast(tr->maxlan*(tr->maxlan+10),&tr->lwork);
 58:   } else {
 59:     PetscBLASIntCast(eps->nloc*(tr->maxlan+1-eps->ncv) + tr->maxlan*(tr->maxlan+10),&tr->lwork);
 60:   }
 61:   PetscMalloc(tr->lwork*sizeof(PetscReal),&tr->work);
 62:   PetscLogObjectMemory(eps,tr->lwork*sizeof(PetscReal));

 64:   if (eps->extraction) { PetscInfo(eps,"Warning: extraction type ignored\n"); }

 66:   EPSAllocateSolution(eps);

 68:   /* dispatch solve method */
 69:   if (eps->leftvecs) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"Left vectors not supported in this solver");
 70:   eps->ops->solve = EPSSolve_TRLAN;
 71:   return(0);
 72: }

 76: static PetscBLASInt MatMult_TRLAN(PetscBLASInt *n,PetscBLASInt *m,PetscReal *xin,PetscBLASInt *ldx,PetscReal *yout,PetscBLASInt *ldy)
 77: {
 79:   Vec            x,y;
 80:   PetscBLASInt   i;

 83:   VecCreateMPIWithArray(PetscObjectComm((PetscObject)globaleps),1,*n,PETSC_DECIDE,NULL,&x);
 84:   VecCreateMPIWithArray(PetscObjectComm((PetscObject)globaleps),1,*n,PETSC_DECIDE,NULL,&y);
 85:   for (i=0;i<*m;i++) {
 86:     VecPlaceArray(x,(PetscScalar*)xin+i*(*ldx));
 87:     VecPlaceArray(y,(PetscScalar*)yout+i*(*ldy));
 88:     STApply(globaleps->st,x,y);
 89:     IPOrthogonalize(globaleps->ip,0,NULL,globaleps->nds,NULL,globaleps->defl,y,NULL,NULL,NULL);
 90:     VecResetArray(x);
 91:     VecResetArray(y);
 92:   }
 93:   VecDestroy(&x);
 94:   VecDestroy(&y);
 95:   return(0);
 96: }

100: PetscErrorCode EPSSolve_TRLAN(EPS eps)
101: {
103:   PetscInt       i;
104:   PetscBLASInt   ipar[32],n,lohi,stat,ncv;
105:   EPS_TRLAN      *tr = (EPS_TRLAN*)eps->data;
106:   PetscScalar    *pV;

109:   PetscBLASIntCast(eps->ncv,&ncv);
110:   PetscBLASIntCast(eps->nloc,&n);

112:   if (eps->which==EPS_LARGEST_REAL || eps->which==EPS_TARGET_REAL) lohi = 1;
113:   else if (eps->which==EPS_SMALLEST_REAL) lohi = -1;
114:   else SETERRQ(PetscObjectComm((PetscObject)eps),1,"Wrong value of eps->which");

116:   globaleps = eps;

118:   ipar[0]  = 0;            /* stat: error flag */
119:   ipar[1]  = lohi;         /* smallest (lohi<0) or largest eigenvalues (lohi>0) */
120:   PetscBLASIntCast(eps->nev,&ipar[2]); /* number of desired eigenpairs */
121:   ipar[3]  = 0;            /* number of eigenpairs already converged */
122:   ipar[4]  = tr->maxlan;   /* maximum Lanczos basis size */
123:   ipar[5]  = tr->restart;  /* restarting scheme */
124:   PetscBLASIntCast(eps->max_it,&ipar[6]); /* maximum number of MATVECs */
125:   PetscBLASIntCast(MPI_Comm_c2f(PetscObjectComm((PetscObject)eps)),&ipar[7]);
126:   ipar[8]  = 0;            /* verboseness */
127:   ipar[9]  = 99;           /* Fortran IO unit number used to write log messages */
128:   ipar[10] = 1;            /* use supplied starting vector */
129:   ipar[11] = 0;            /* checkpointing flag */
130:   ipar[12] = 98;           /* Fortran IO unit number used to write checkpoint files */
131:   ipar[13] = 0;            /* number of flops per matvec per PE (not used) */
132:   tr->work[0] = eps->tol;  /* relative tolerance on residual norms */

134:   for (i=0;i<eps->ncv;i++) eps->eigr[i]=0.0;
135:   EPSGetStartVector(eps,0,eps->V[0],NULL);
136:   VecGetArray(eps->V[0],&pV);

138:   PetscStackCall("TRLan",TRLan_(MatMult_TRLAN,ipar,&n,&ncv,eps->eigr,pV,&n,tr->work,&tr->lwork));

140:   VecRestoreArray(eps->V[0],&pV);

142:   stat        = ipar[0];
143:   eps->nconv  = ipar[3];
144:   eps->its    = ipar[25];
145:   eps->reason = EPS_CONVERGED_TOL;

147:   if (stat!=0) SETERRQ1(PetscObjectComm((PetscObject)eps),PETSC_ERR_LIB,"Error in TRLAN (code=%d)",stat);
148:   return(0);
149: }

153: PetscErrorCode EPSReset_TRLAN(EPS eps)
154: {
156:   EPS_TRLAN      *tr = (EPS_TRLAN*)eps->data;

159:   PetscFree(tr->work);
160:   EPSFreeSolution(eps);
161:   return(0);
162: }

166: PetscErrorCode EPSDestroy_TRLAN(EPS eps)
167: {

171:   PetscFree(eps->data);
172:   return(0);
173: }

177: PETSC_EXTERN PetscErrorCode EPSCreate_TRLAN(EPS eps)
178: {

182:   PetscNewLog(eps,EPS_TRLAN,&eps->data);
183:   eps->ops->setup                = EPSSetUp_TRLAN;
184:   eps->ops->destroy              = EPSDestroy_TRLAN;
185:   eps->ops->reset                = EPSReset_TRLAN;
186:   eps->ops->backtransform        = EPSBackTransform_Default;
187:   eps->ops->computevectors       = EPSComputeVectors_Default;
188:   return(0);
189: }