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) 2002-2011, Universitat Politecnica de Valencia, Spain

  8:    This file is part of SLEPc.
  9:       
 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 <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:   tr->maxlan = PetscBLASIntCast(PetscMax(7,eps->nev+PetscMin(eps->nev,6)));
 41:   if (eps->ncv) {
 42:     if (eps->ncv<eps->nev) SETERRQ(((PetscObject)eps)->comm,1,"The value of ncv must be at least nev");
 43:   }
 44:   else eps->ncv = tr->maxlan;
 45:   if (eps->mpd) { PetscInfo(eps,"Warning: parameter mpd ignored\n"); }
 46:   if (!eps->max_it) eps->max_it = PetscMax(1000,eps->n);
 47: 
 48:   if (!eps->ishermitian)
 49:     SETERRQ(((PetscObject)eps)->comm,PETSC_ERR_SUP,"Requested method is only available for Hermitian problems");

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

 54:   if (!eps->which) eps->which = EPS_LARGEST_REAL;
 55:   if (eps->which!=EPS_LARGEST_REAL && eps->which!=EPS_SMALLEST_REAL && eps->which!=EPS_TARGET_REAL)
 56:     SETERRQ(((PetscObject)eps)->comm,1,"Wrong value of eps->which");

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

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

 65:   EPSAllocateSolution(eps);

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

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

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

 99: PetscErrorCode EPSSolve_TRLAN(EPS eps)
100: {
102:   PetscInt       i;
103:   PetscBLASInt   ipar[32],n,lohi,stat,ncv;
104:   EPS_TRLAN      *tr = (EPS_TRLAN *)eps->data;
105:   PetscScalar    *pV;
106: 
108:   ncv = PetscBLASIntCast(eps->ncv);
109:   n = PetscBLASIntCast(eps->nloc);
110: 
111:   if (eps->which==EPS_LARGEST_REAL || eps->which==EPS_TARGET_REAL) lohi = 1;
112:   else if (eps->which==EPS_SMALLEST_REAL) lohi = -1;
113:   else SETERRQ(((PetscObject)eps)->comm,1,"Wrong value of eps->which");

115:   globaleps = eps;

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

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

137:   TRLan_(MatMult_TRLAN,ipar,&n,&ncv,eps->eigr,pV,&n,tr->work,&tr->lwork);

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

141:   stat        = ipar[0];
142:   eps->nconv  = ipar[3];
143:   eps->its    = ipar[25];
144:   eps->reason = EPS_CONVERGED_TOL;
145: 
146:   if (stat!=0) { SETERRQ1(((PetscObject)eps)->comm,PETSC_ERR_LIB,"Error in TRLAN (code=%d)",stat);}
147:   return(0);
148: }

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

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

165: PetscErrorCode EPSDestroy_TRLAN(EPS eps)
166: {

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

174: EXTERN_C_BEGIN
177: 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: }
190: EXTERN_C_END