Actual source code: elemental.cxx

      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 eigensolvers in Elemental.
     12: */

     14: #include <slepc/private/epsimpl.h>
     15: #include <petsc/private/petscelemental.h>

     17: typedef struct {
     18:   Mat Ae,Be;        /* converted matrices */
     19: } EPS_Elemental;

     21: static PetscErrorCode EPSSetUp_Elemental(EPS eps)
     22: {
     23:   EPS_Elemental  *ctx = (EPS_Elemental*)eps->data;
     24:   Mat            A,B;
     25:   PetscInt       nmat;
     26:   PetscBool      isshift;
     27:   PetscScalar    shift;

     29:   PetscFunctionBegin;
     30:   EPSCheckHermitianDefinite(eps);
     31:   EPSCheckNotStructured(eps);
     32:   PetscCall(PetscObjectTypeCompare((PetscObject)eps->st,STSHIFT,&isshift));
     33:   PetscCheck(isshift,PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"This solver does not support spectral transformations");
     34:   if (eps->nev==0) eps->nev = 1;
     35:   eps->ncv = eps->n;
     36:   if (eps->mpd!=PETSC_DETERMINE) PetscCall(PetscInfo(eps,"Warning: parameter mpd ignored\n"));
     37:   if (eps->max_it==PETSC_DETERMINE) eps->max_it = 1;
     38:   if (!eps->which) PetscCall(EPSSetWhichEigenpairs_Default(eps));
     39:   PetscCheck(eps->which!=EPS_ALL || eps->inta==eps->intb,PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"This solver does not support interval computation");
     40:   EPSCheckUnsupported(eps,EPS_FEATURE_BALANCE | EPS_FEATURE_ARBITRARY | EPS_FEATURE_REGION);
     41:   EPSCheckIgnored(eps,EPS_FEATURE_EXTRACTION | EPS_FEATURE_CONVERGENCE | EPS_FEATURE_STOPPING);
     42:   PetscCall(EPSAllocateSolution(eps,0));

     44:   /* convert matrices */
     45:   PetscCall(MatDestroy(&ctx->Ae));
     46:   PetscCall(MatDestroy(&ctx->Be));
     47:   PetscCall(STGetNumMatrices(eps->st,&nmat));
     48:   PetscCall(STGetMatrix(eps->st,0,&A));
     49:   PetscCall(MatConvert(A,MATELEMENTAL,MAT_INITIAL_MATRIX,&ctx->Ae));
     50:   if (nmat>1) {
     51:     PetscCall(STGetMatrix(eps->st,1,&B));
     52:     PetscCall(MatConvert(B,MATELEMENTAL,MAT_INITIAL_MATRIX,&ctx->Be));
     53:   }
     54:   PetscCall(STGetShift(eps->st,&shift));
     55:   if (shift != 0.0) {
     56:     if (nmat>1) PetscCall(MatAXPY(ctx->Ae,-shift,ctx->Be,SAME_NONZERO_PATTERN));
     57:     else PetscCall(MatShift(ctx->Ae,-shift));
     58:   }
     59:   PetscFunctionReturn(PETSC_SUCCESS);
     60: }

     62: static PetscErrorCode EPSSolve_Elemental(EPS eps)
     63: {
     64:   EPS_Elemental  *ctx = (EPS_Elemental*)eps->data;
     65:   Mat            A = ctx->Ae,B = ctx->Be,Q,V;
     66:   Mat_Elemental  *a = (Mat_Elemental*)A->data,*b,*q;
     67:   PetscInt       i,rrank,ridx,erow;

     69:   PetscFunctionBegin;
     70:   El::DistMatrix<PetscReal,El::VR,El::STAR> w(*a->grid);
     71:   PetscCall(MatDuplicate(A,MAT_DO_NOT_COPY_VALUES,&Q));
     72:   q = (Mat_Elemental*)Q->data;

     74:   if (B) {
     75:     b = (Mat_Elemental*)B->data;
     76:     El::HermitianGenDefEig(El::AXBX,El::LOWER,*a->emat,*b->emat,w,*q->emat);
     77:   } else El::HermitianEig(El::LOWER,*a->emat,w,*q->emat);

     79:   for (i=0;i<eps->ncv;i++) {
     80:     P2RO(A,0,i,&rrank,&ridx);
     81:     RO2E(A,0,rrank,ridx,&erow);
     82:     eps->eigr[i] = w.Get(erow,0);
     83:   }
     84:   PetscCall(BVGetMat(eps->V,&V));
     85:   PetscCall(MatConvert(Q,MATDENSE,MAT_REUSE_MATRIX,&V));
     86:   PetscCall(BVRestoreMat(eps->V,&V));
     87:   PetscCall(MatDestroy(&Q));

     89:   eps->nconv  = eps->ncv;
     90:   eps->its    = 1;
     91:   eps->reason = EPS_CONVERGED_TOL;
     92:   PetscFunctionReturn(PETSC_SUCCESS);
     93: }

     95: static PetscErrorCode EPSDestroy_Elemental(EPS eps)
     96: {
     97:   PetscFunctionBegin;
     98:   PetscCall(PetscFree(eps->data));
     99:   PetscFunctionReturn(PETSC_SUCCESS);
    100: }

    102: static PetscErrorCode EPSReset_Elemental(EPS eps)
    103: {
    104:   EPS_Elemental  *ctx = (EPS_Elemental*)eps->data;

    106:   PetscFunctionBegin;
    107:   PetscCall(MatDestroy(&ctx->Ae));
    108:   PetscCall(MatDestroy(&ctx->Be));
    109:   PetscFunctionReturn(PETSC_SUCCESS);
    110: }

    112: /*MC
    113:    EPSELEMENTAL - EPSELEMENTAL = "elemental" - A wrapper to Elemental
    114:    eigensolvers {cite:p}`Pou13`.

    116:    Notes:
    117:    Only available for Hermitian problems.

    119:    Elemental contains a direct eigensolver, that is, the full spectrum
    120:    is computed. Its storage format is similar to ScaLAPACK, but different,
    121:    and it may have better parallel performance in some cases. The
    122:    SLEPc solver is also in charge of the redistribution of matrices.

    124:    Level: beginner

    126: .seealso: [](ch:eps), `EPS`, `EPSType`, `EPSSetType()`
    127: M*/
    128: SLEPC_EXTERN PetscErrorCode EPSCreate_Elemental(EPS eps)
    129: {
    130:   EPS_Elemental  *ctx;

    132:   PetscFunctionBegin;
    133:   PetscCall(PetscNew(&ctx));
    134:   eps->data = (void*)ctx;

    136:   eps->categ = EPS_CATEGORY_OTHER;

    138:   eps->ops->solve          = EPSSolve_Elemental;
    139:   eps->ops->setup          = EPSSetUp_Elemental;
    140:   eps->ops->setupsort      = EPSSetUpSort_Basic;
    141:   eps->ops->destroy        = EPSDestroy_Elemental;
    142:   eps->ops->reset          = EPSReset_Elemental;
    143:   eps->ops->backtransform  = EPSBackTransform_Default;
    144:   eps->ops->setdefaultst   = EPSSetDefaultST_NoFactor;
    145:   PetscFunctionReturn(PETSC_SUCCESS);
    146: }