Actual source code: trlan.c

slepc-3.11.2 2019-07-30
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  1: /*
  2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
  4:    Copyright (c) 2002-2019, Universitat Politecnica de Valencia, Spain

  6:    This file is part of SLEPc.
  7:    SLEPc is distributed under a 2-clause BSD license (see LICENSE).
  8:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  9: */
 10: /*
 11:    This file implements a wrapper to the TRLAN package
 12: */

 14: #include <slepc/private/epsimpl.h>
 15: #include <../src/eps/impls/external/trlan/trlanp.h>

 17: /* Nasty global variable to access EPS data from TRLan_ */
 18: static struct {
 19:   EPS eps;
 20:   Vec x,y;
 21: } globaldata;

 23: PetscErrorCode EPSSetUp_TRLAN(EPS eps)
 24: {
 26:   PetscBool      istrivial;
 27:   EPS_TRLAN      *tr = (EPS_TRLAN*)eps->data;

 30:   PetscBLASIntCast(PetscMax(7,eps->nev+PetscMin(eps->nev,6)),&tr->maxlan);
 31:   if (eps->ncv) {
 32:     if (eps->ncv<eps->nev) SETERRQ(PetscObjectComm((PetscObject)eps),1,"The value of ncv must be at least nev");
 33:   } else eps->ncv = tr->maxlan;
 34:   if (eps->mpd) { PetscInfo(eps,"Warning: parameter mpd ignored\n"); }
 35:   if (!eps->max_it) eps->max_it = PetscMax(1000,eps->n);

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

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

 41:   if (!eps->which) eps->which = EPS_LARGEST_REAL;
 42:   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");
 43:   if (eps->arbitrary) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"Arbitrary selection of eigenpairs not supported in this solver");
 44:   if (eps->stopping!=EPSStoppingBasic) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"External packages do not support user-defined stopping test");

 46:   tr->restart = 0;
 47:   if (tr->maxlan+1-eps->ncv<=0) {
 48:     PetscBLASIntCast(tr->maxlan*(tr->maxlan+10),&tr->lwork);
 49:   } else {
 50:     PetscBLASIntCast(eps->nloc*(tr->maxlan+1-eps->ncv) + tr->maxlan*(tr->maxlan+10),&tr->lwork);
 51:   }
 52:   if (tr->work) { PetscFree(tr->work); }
 53:   PetscMalloc1(tr->lwork,&tr->work);
 54:   PetscLogObjectMemory((PetscObject)eps,tr->lwork*sizeof(PetscReal));

 56:   if (eps->extraction) { PetscInfo(eps,"Warning: extraction type ignored\n"); }
 57:   RGIsTrivial(eps->rg,&istrivial);
 58:   if (!istrivial) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"This solver does not support region filtering");

 60:   EPSAllocateSolution(eps,0);
 61:   return(0);
 62: }

 64: static PetscBLASInt MatMult_TRLAN(PetscBLASInt *n,PetscBLASInt *m,PetscReal *xin,PetscBLASInt *ldx,PetscReal *yout,PetscBLASInt *ldy)
 65: {
 67:   Vec            x=globaldata.x,y=globaldata.y;
 68:   EPS            eps=globaldata.eps;
 69:   PetscBLASInt   i;

 72:   for (i=0;i<*m;i++) {
 73:     VecPlaceArray(x,(PetscScalar*)xin+i*(*ldx));
 74:     VecPlaceArray(y,(PetscScalar*)yout+i*(*ldy));
 75:     STApply(eps->st,x,y);
 76:     BVOrthogonalizeVec(eps->V,y,NULL,NULL,NULL);
 77:     VecResetArray(x);
 78:     VecResetArray(y);
 79:   }
 80:   return(0);
 81: }

 83: PetscErrorCode EPSSolve_TRLAN(EPS eps)
 84: {
 86:   PetscInt       i;
 87:   PetscBLASInt   ipar[32],n,lohi,stat,ncv;
 88:   EPS_TRLAN      *tr = (EPS_TRLAN*)eps->data;
 89:   PetscScalar    *pV;
 90:   Vec            v0;
 91:   Mat            A;

 94:   PetscBLASIntCast(eps->ncv,&ncv);
 95:   PetscBLASIntCast(eps->nloc,&n);

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

101:   globaldata.eps = eps;
102:   STGetMatrix(eps->st,0,&A);
103:   MatCreateVecsEmpty(A,&globaldata.x,&globaldata.y);

105:   ipar[0]  = 0;            /* stat: error flag */
106:   ipar[1]  = lohi;         /* smallest (lohi<0) or largest eigenvalues (lohi>0) */
107:   PetscBLASIntCast(eps->nev,&ipar[2]); /* number of desired eigenpairs */
108:   ipar[3]  = 0;            /* number of eigenpairs already converged */
109:   ipar[4]  = tr->maxlan;   /* maximum Lanczos basis size */
110:   ipar[5]  = tr->restart;  /* restarting scheme */
111:   PetscBLASIntCast(eps->max_it,&ipar[6]); /* maximum number of MATVECs */
112: #if !defined(PETSC_HAVE_MPIUNI)
113:   PetscBLASIntCast(MPI_Comm_c2f(PetscObjectComm((PetscObject)eps)),&ipar[7]);
114: #endif
115:   ipar[8]  = 0;            /* verboseness */
116:   ipar[9]  = 99;           /* Fortran IO unit number used to write log messages */
117:   ipar[10] = 1;            /* use supplied starting vector */
118:   ipar[11] = 0;            /* checkpointing flag */
119:   ipar[12] = 98;           /* Fortran IO unit number used to write checkpoint files */
120:   ipar[13] = 0;            /* number of flops per matvec per PE (not used) */
121:   tr->work[0] = eps->tol;  /* relative tolerance on residual norms */

123:   for (i=0;i<eps->ncv;i++) eps->eigr[i]=0.0;
124:   EPSGetStartVector(eps,0,NULL);
125:   BVSetActiveColumns(eps->V,0,0);  /* just for deflation space */
126:   BVGetColumn(eps->V,0,&v0);
127:   VecGetArray(v0,&pV);

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

131:   VecRestoreArray(v0,&pV);
132:   BVRestoreColumn(eps->V,0,&v0);

134:   stat        = ipar[0];
135:   eps->nconv  = ipar[3];
136:   eps->its    = ipar[25];
137:   eps->reason = EPS_CONVERGED_TOL;

139:   VecDestroy(&globaldata.x);
140:   VecDestroy(&globaldata.y);
141:   if (stat!=0) SETERRQ1(PetscObjectComm((PetscObject)eps),PETSC_ERR_LIB,"Error in TRLAN (code=%d)",stat);
142:   return(0);
143: }

145: PetscErrorCode EPSReset_TRLAN(EPS eps)
146: {
148:   EPS_TRLAN      *tr = (EPS_TRLAN*)eps->data;

151:   PetscFree(tr->work);
152:   return(0);
153: }

155: PetscErrorCode EPSDestroy_TRLAN(EPS eps)
156: {

160:   PetscFree(eps->data);
161:   return(0);
162: }

164: SLEPC_EXTERN PetscErrorCode EPSCreate_TRLAN(EPS eps)
165: {
166:   EPS_TRLAN      *ctx;

170:   PetscNewLog(eps,&ctx);
171:   eps->data = (void*)ctx;

173:   eps->ops->solve          = EPSSolve_TRLAN;
174:   eps->ops->setup          = EPSSetUp_TRLAN;
175:   eps->ops->destroy        = EPSDestroy_TRLAN;
176:   eps->ops->reset          = EPSReset_TRLAN;
177:   eps->ops->backtransform  = EPSBackTransform_Default;
178:   return(0);
179: }