Date: 2022-11-02T11:46:48+00:00

Actual source code: arpack.c
slepc-3.18.1 2022-11-02
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      1: /*
      2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
      3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
      4:    Copyright (c) 2002-, 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 ARPACK package
     12: */

     14: #include <slepc/private/epsimpl.h>
     15: #include "arpack.h"

     17: PetscErrorCode EPSSetUp_ARPACK(EPS eps)
     18: {
     19:   PetscInt       ncv;
     20:   EPS_ARPACK     *ar = (EPS_ARPACK*)eps->data;

     22:   EPSCheckDefinite(eps);
     23:   if (eps->ncv!=PETSC_DEFAULT) {
     25:   } else eps->ncv = PetscMin(PetscMax(20,2*eps->nev+1),eps->n); /* set default value of ncv */
     26:   if (eps->mpd!=PETSC_DEFAULT) PetscInfo(eps,"Warning: parameter mpd ignored\n");
     27:   if (eps->max_it==PETSC_DEFAULT) eps->max_it = PetscMax(300,(PetscInt)(2*eps->n/eps->ncv));
     28:   if (!eps->which) EPSSetWhichEigenpairs_Default(eps);
     31:   EPSCheckUnsupported(eps,EPS_FEATURE_BALANCE | EPS_FEATURE_ARBITRARY | EPS_FEATURE_REGION | EPS_FEATURE_CONVERGENCE | EPS_FEATURE_STOPPING | EPS_FEATURE_TWOSIDED);
     32:   EPSCheckIgnored(eps,EPS_FEATURE_EXTRACTION);

     34:   ncv = eps->ncv;
     35: #if defined(PETSC_USE_COMPLEX)
     36:   PetscFree(ar->rwork);
     37:   PetscMalloc1(ncv,&ar->rwork);
     38:   ar->lworkl = 3*ncv*ncv+5*ncv;
     39:   PetscFree(ar->workev);
     40:   PetscMalloc1(3*ncv,&ar->workev);
     41: #else
     42:   if (eps->ishermitian) {
     43:     ar->lworkl = ncv*(ncv+8);
     44:   } else {
     45:     ar->lworkl = 3*ncv*ncv+6*ncv;
     46:     PetscFree(ar->workev);
     47:     PetscMalloc1(3*ncv,&ar->workev);
     48:   }
     49: #endif
     50:   PetscFree(ar->workl);
     51:   PetscMalloc1(ar->lworkl,&ar->workl);
     52:   PetscFree(ar->select);
     53:   PetscMalloc1(ncv,&ar->select);
     54:   PetscFree(ar->workd);
     55:   PetscMalloc1(3*eps->nloc,&ar->workd);

     57:   EPSAllocateSolution(eps,0);
     58:   EPS_SetInnerProduct(eps);
     59:   EPSSetWorkVecs(eps,2);
     60:   return 0;
     61: }

     63: PetscErrorCode EPSSolve_ARPACK(EPS eps)
     64: {
     65:   EPS_ARPACK     *ar = (EPS_ARPACK*)eps->data;
     66:   char           bmat[1],howmny[] = "A";
     67:   const char     *which;
     68:   PetscInt       n,iparam[11],ipntr[14],ido,info,nev,ncv,rvec;
     69: #if !defined(PETSC_HAVE_MPIUNI) && !defined(PETSC_HAVE_MSMPI)
     70:   MPI_Fint       fcomm;
     71: #endif
     72:   PetscScalar    sigmar,*pV,*resid;
     73:   Vec            x,y,w = eps->work[0];
     74:   Mat            A;
     75:   PetscBool      isSinv,isShift;
     76: #if !defined(PETSC_USE_COMPLEX)
     77:   PetscScalar    sigmai = 0.0;
     78: #endif

     80:   nev = eps->nev;
     81:   ncv = eps->ncv;
     82: #if !defined(PETSC_HAVE_MPIUNI) && !defined(PETSC_HAVE_MSMPI)
     83:   fcomm = MPI_Comm_c2f(PetscObjectComm((PetscObject)eps));
     84: #endif
     85:   n = eps->nloc;
     86:   EPSGetStartVector(eps,0,NULL);
     87:   BVSetActiveColumns(eps->V,0,0);  /* just for deflation space */
     88:   BVCopyVec(eps->V,0,eps->work[1]);
     89:   BVGetArray(eps->V,&pV);
     90:   VecGetArray(eps->work[1],&resid);

     92:   ido  = 0;            /* first call to reverse communication interface */
     93:   info = 1;            /* indicates an initial vector is provided */
     94:   iparam[0] = 1;       /* use exact shifts */
     95:   iparam[2] = eps->max_it;  /* max Arnoldi iterations */
     96:   iparam[3] = 1;       /* blocksize */
     97:   iparam[4] = 0;       /* number of converged Ritz values */

     99:   /*
    100:      Computational modes ([]=not supported):
    101:             symmetric    non-symmetric    complex
    102:         1     1  'I'        1  'I'         1  'I'
    103:         2     3  'I'        3  'I'         3  'I'
    104:         3     2  'G'        2  'G'         2  'G'
    105:         4     3  'G'        3  'G'         3  'G'
    106:         5   [ 4  'G' ]    [ 3  'G' ]
    107:         6   [ 5  'G' ]    [ 4  'G' ]
    108:    */
    109:   PetscObjectTypeCompare((PetscObject)eps->st,STSINVERT,&isSinv);
    110:   PetscObjectTypeCompare((PetscObject)eps->st,STSHIFT,&isShift);
    111:   STGetShift(eps->st,&sigmar);
    112:   STGetMatrix(eps->st,0,&A);
    113:   MatCreateVecsEmpty(A,&x,&y);

    115:   if (isSinv) {
    116:     /* shift-and-invert mode */
    117:     iparam[6] = 3;
    118:     if (eps->ispositive) bmat[0] = 'G';
    119:     else bmat[0] = 'I';
    120:   } else if (isShift && eps->ispositive) {
    121:     /* generalized shift mode with B positive definite */
    122:     iparam[6] = 2;
    123:     bmat[0] = 'G';
    124:   } else {
    125:     /* regular mode */
    127:     iparam[6] = 1;
    128:     bmat[0] = 'I';
    129:   }

    131: #if !defined(PETSC_USE_COMPLEX)
    132:   if (eps->ishermitian) {
    133:     switch (eps->which) {
    134:       case EPS_TARGET_MAGNITUDE:
    135:       case EPS_LARGEST_MAGNITUDE:  which = "LM"; break;
    136:       case EPS_SMALLEST_MAGNITUDE: which = "SM"; break;
    137:       case EPS_TARGET_REAL:
    138:       case EPS_LARGEST_REAL:       which = "LA"; break;
    139:       case EPS_SMALLEST_REAL:      which = "SA"; break;
    140:       default: SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_WRONG,"Wrong value of eps->which");
    141:     }
    142:   } else {
    143: #endif
    144:     switch (eps->which) {
    145:       case EPS_TARGET_MAGNITUDE:
    146:       case EPS_LARGEST_MAGNITUDE:  which = "LM"; break;
    147:       case EPS_SMALLEST_MAGNITUDE: which = "SM"; break;
    148:       case EPS_TARGET_REAL:
    149:       case EPS_LARGEST_REAL:       which = "LR"; break;
    150:       case EPS_SMALLEST_REAL:      which = "SR"; break;
    151:       case EPS_TARGET_IMAGINARY:
    152:       case EPS_LARGEST_IMAGINARY:  which = "LI"; break;
    153:       case EPS_SMALLEST_IMAGINARY: which = "SI"; break;
    154:       default: SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_WRONG,"Wrong value of eps->which");
    155:     }
    156: #if !defined(PETSC_USE_COMPLEX)
    157:   }
    158: #endif

    160:   do {

    162: #if !defined(PETSC_USE_COMPLEX)
    163:     if (eps->ishermitian) {
    164:       PetscStackCallExternalVoid("ARPACKsaupd",ARPACKsaupd_(&fcomm,&ido,bmat,&n,which,&nev,&eps->tol,resid,&ncv,pV,&n,iparam,ipntr,ar->workd,ar->workl,&ar->lworkl,&info));
    165:     } else {
    166:       PetscStackCallExternalVoid("ARPACKnaupd",ARPACKnaupd_(&fcomm,&ido,bmat,&n,which,&nev,&eps->tol,resid,&ncv,pV,&n,iparam,ipntr,ar->workd,ar->workl,&ar->lworkl,&info));
    167:     }
    168: #else
    169:     PetscStackCallExternalVoid("ARPACKnaupd",ARPACKnaupd_(&fcomm,&ido,bmat,&n,which,&nev,&eps->tol,resid,&ncv,pV,&n,iparam,ipntr,ar->workd,ar->workl,&ar->lworkl,ar->rwork,&info));
    170: #endif

    172:     if (ido == -1 || ido == 1 || ido == 2) {
    173:       if (ido == 1 && iparam[6] == 3 && bmat[0] == 'G') VecPlaceArray(x,&ar->workd[ipntr[2]-1]); /* special case for shift-and-invert with B semi-positive definite*/
    174:       else VecPlaceArray(x,&ar->workd[ipntr[0]-1]);
    175:       VecPlaceArray(y,&ar->workd[ipntr[1]-1]);

    177:       if (ido == -1) {
    178:         /* Y = OP * X for for the initialization phase to
    179:            force the starting vector into the range of OP */
    180:         STApply(eps->st,x,y);
    181:       } else if (ido == 2) {
    182:         /* Y = B * X */
    183:         BVApplyMatrix(eps->V,x,y);
    184:       } else { /* ido == 1 */
    185:         if (iparam[6] == 3 && bmat[0] == 'G') {
    186:           /* Y = OP * X for shift-and-invert with B semi-positive definite */
    187:           STMatSolve(eps->st,x,y);
    188:         } else if (iparam[6] == 2) {
    189:           /* X=A*X Y=B^-1*X for shift with B positive definite */
    190:           MatMult(A,x,y);
    191:           if (sigmar != 0.0) {
    192:             BVApplyMatrix(eps->V,x,w);
    193:             VecAXPY(y,sigmar,w);
    194:           }
    195:           VecCopy(y,x);
    196:           STMatSolve(eps->st,x,y);
    197:         } else {
    198:           /* Y = OP * X */
    199:           STApply(eps->st,x,y);
    200:         }
    201:         BVOrthogonalizeVec(eps->V,y,NULL,NULL,NULL);
    202:       }

    204:       VecResetArray(x);
    205:       VecResetArray(y);

    208:   } while (ido != 99);

    210:   eps->nconv = iparam[4];
    211:   eps->its = iparam[2];

    216:   rvec = PETSC_TRUE;

    218:   if (eps->nconv > 0) {
    219: #if !defined(PETSC_USE_COMPLEX)
    220:     if (eps->ishermitian) {
    221:       PetscStackCallExternalVoid("ARPACKseupd",ARPACKseupd_(&fcomm,&rvec,howmny,ar->select,eps->eigr,pV,&n,&sigmar,bmat,&n,which,&nev,&eps->tol,resid,&ncv,pV,&n,iparam,ipntr,ar->workd,ar->workl,&ar->lworkl,&info));
    222:     } else {
    223:       PetscStackCallExternalVoid("ARPACKneupd",ARPACKneupd_(&fcomm,&rvec,howmny,ar->select,eps->eigr,eps->eigi,pV,&n,&sigmar,&sigmai,ar->workev,bmat,&n,which,&nev,&eps->tol,resid,&ncv,pV,&n,iparam,ipntr,ar->workd,ar->workl,&ar->lworkl,&info));
    224:     }
    225: #else
    226:     PetscStackCallExternalVoid("ARPACKneupd",ARPACKneupd_(&fcomm,&rvec,howmny,ar->select,eps->eigr,pV,&n,&sigmar,ar->workev,bmat,&n,which,&nev,&eps->tol,resid,&ncv,pV,&n,iparam,ipntr,ar->workd,ar->workl,&ar->lworkl,ar->rwork,&info));
    227: #endif
    229:   }

    231:   BVRestoreArray(eps->V,&pV);
    232:   VecRestoreArray(eps->work[1],&resid);
    233:   if (eps->nconv >= eps->nev) eps->reason = EPS_CONVERGED_TOL;
    234:   else eps->reason = EPS_DIVERGED_ITS;

    236:   VecDestroy(&x);
    237:   VecDestroy(&y);
    238:   return 0;
    239: }

    241: PetscErrorCode EPSBackTransform_ARPACK(EPS eps)
    242: {
    243:   PetscBool      isSinv;

    245:   PetscObjectTypeCompare((PetscObject)eps->st,STSINVERT,&isSinv);
    246:   if (!isSinv) EPSBackTransform_Default(eps);
    247:   return 0;
    248: }

    250: PetscErrorCode EPSReset_ARPACK(EPS eps)
    251: {
    252:   EPS_ARPACK     *ar = (EPS_ARPACK*)eps->data;

    254:   PetscFree(ar->workev);
    255:   PetscFree(ar->workl);
    256:   PetscFree(ar->select);
    257:   PetscFree(ar->workd);
    258: #if defined(PETSC_USE_COMPLEX)
    259:   PetscFree(ar->rwork);
    260: #endif
    261:   return 0;
    262: }

    264: PetscErrorCode EPSDestroy_ARPACK(EPS eps)
    265: {
    266:   PetscFree(eps->data);
    267:   return 0;
    268: }

    270: SLEPC_EXTERN PetscErrorCode EPSCreate_ARPACK(EPS eps)
    271: {
    272:   EPS_ARPACK     *ctx;

    274:   PetscNew(&ctx);
    275:   eps->data = (void*)ctx;

    277:   eps->ops->solve          = EPSSolve_ARPACK;
    278:   eps->ops->setup          = EPSSetUp_ARPACK;
    279:   eps->ops->setupsort      = EPSSetUpSort_Basic;
    280:   eps->ops->destroy        = EPSDestroy_ARPACK;
    281:   eps->ops->reset          = EPSReset_ARPACK;
    282:   eps->ops->backtransform  = EPSBackTransform_ARPACK;
    283:   return 0;
    284: }