Date: 2016-03-29T14:57:16+00:00

Actual source code: test1.c
slepc-3.6.3 2016-03-29
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      1: /*
      2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
      3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
      4:    Copyright (c) 2002-2015, Universitat Politecnica de Valencia, Spain

      6:    This file is part of SLEPc.

      8:    SLEPc is free software: you can redistribute it and/or modify it under  the
      9:    terms of version 3 of the GNU Lesser General Public License as published by
     10:    the Free Software Foundation.

     12:    SLEPc  is  distributed in the hope that it will be useful, but WITHOUT  ANY
     13:    WARRANTY;  without even the implied warranty of MERCHANTABILITY or  FITNESS
     14:    FOR  A  PARTICULAR PURPOSE. See the GNU Lesser General Public  License  for
     15:    more details.

     17:    You  should have received a copy of the GNU Lesser General  Public  License
     18:    along with SLEPc. If not, see <http://www.gnu.org/licenses/>.
     19:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     20: */

     22: static char help[] = "Test ST with shell matrices.\n\n";

     24: #include <slepcst.h>

     26: static PetscErrorCode MatGetDiagonal_Shell(Mat S,Vec diag);
     27: static PetscErrorCode MatMultTranspose_Shell(Mat S,Vec x,Vec y);
     28: static PetscErrorCode MatMult_Shell(Mat S,Vec x,Vec y);
     29: static PetscErrorCode MatDuplicate_Shell(Mat S,MatDuplicateOption op,Mat *M);

     33: static PetscErrorCode MyShellMatCreate(Mat *A,Mat *M)
     34: {
     36:   MPI_Comm       comm;
     37:   PetscInt       n;

     40:   MatGetSize(*A,&n,NULL);
     41:   PetscObjectGetComm((PetscObject)*A,&comm);
     42:   MatCreateShell(comm,PETSC_DECIDE,PETSC_DECIDE,n,n,A,M);
     43:   MatSetFromOptions(*M);
     44:   MatShellSetOperation(*M,MATOP_MULT,(void(*)())MatMult_Shell);
     45:   MatShellSetOperation(*M,MATOP_MULT_TRANSPOSE,(void(*)())MatMultTranspose_Shell);
     46:   MatShellSetOperation(*M,MATOP_GET_DIAGONAL,(void(*)())MatGetDiagonal_Shell);
     47:   MatShellSetOperation(*M,MATOP_DUPLICATE,(void(*)())MatDuplicate_Shell);
     48:   return(0);
     49: }

     53: int main(int argc,char **argv)
     54: {
     55:   Mat            A,S,mat[1];
     56:   ST             st;
     57:   Vec            v,w;
     58:   STType         type;
     59:   KSP            ksp;
     60:   PC             pc;
     61:   PetscScalar    sigma;
     62:   PetscInt       n=10,i,Istart,Iend;

     65:   SlepcInitialize(&argc,&argv,(char*)0,help);
     66:   PetscOptionsGetInt(NULL,"-n",&n,NULL);
     67:   PetscPrintf(PETSC_COMM_WORLD,"\n1-D Laplacian with shell matrices, n=%D\n\n",n);

     69:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     70:      Compute the operator matrix for the 1-D Laplacian
     71:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

     73:   MatCreate(PETSC_COMM_WORLD,&A);
     74:   MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,n,n);
     75:   MatSetFromOptions(A);
     76:   MatSetUp(A);

     78:   MatGetOwnershipRange(A,&Istart,&Iend);
     79:   for (i=Istart;i<Iend;i++) {
     80:     if (i>0) { MatSetValue(A,i,i-1,-1.0,INSERT_VALUES); }
     81:     if (i<n-1) { MatSetValue(A,i,i+1,-1.0,INSERT_VALUES); }
     82:     MatSetValue(A,i,i,2.0,INSERT_VALUES);
     83:   }
     84:   MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
     85:   MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);

     87:   /* create the shell version of A */
     88:   MyShellMatCreate(&A,&S);

     90:   /* work vectors */
     91:   MatCreateVecs(A,&v,&w);
     92:   VecSet(v,1.0);

     94:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     95:                 Create the spectral transformation object
     96:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

     98:   STCreate(PETSC_COMM_WORLD,&st);
     99:   mat[0] = S;
    100:   STSetOperators(st,1,mat);
    101:   STSetTransform(st,PETSC_TRUE);
    102:   STSetFromOptions(st);

    105:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
    106:               Apply the transformed operator for several ST's
    107:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

    109:   /* shift, sigma=0.0 */
    110:   STSetUp(st);
    111:   STGetType(st,&type);
    112:   PetscPrintf(PETSC_COMM_WORLD,"ST type %s\n",type);
    113:   STApply(st,v,w);
    114:   VecView(w,NULL);

    116:   /* shift, sigma=0.1 */
    117:   sigma = 0.1;
    118:   STSetShift(st,sigma);
    119:   STGetShift(st,&sigma);
    120:   PetscPrintf(PETSC_COMM_WORLD,"With shift=%g\n",(double)PetscRealPart(sigma));
    121:   STApply(st,v,w);
    122:   VecView(w,NULL);

    124:   /* sinvert, sigma=0.1 */
    125:   STPostSolve(st);   /* undo changes if inplace */
    126:   STSetType(st,STSINVERT);
    127:   STGetKSP(st,&ksp);
    128:   KSPSetType(ksp,KSPGMRES);
    129:   KSPGetPC(ksp,&pc);
    130:   PCSetType(pc,PCJACOBI);
    131:   STGetType(st,&type);
    132:   PetscPrintf(PETSC_COMM_WORLD,"ST type %s\n",type);
    133:   STGetShift(st,&sigma);
    134:   PetscPrintf(PETSC_COMM_WORLD,"With shift=%g\n",(double)PetscRealPart(sigma));
    135:   STApply(st,v,w);
    136:   VecView(w,NULL);

    138:   /* sinvert, sigma=-0.5 */
    139:   sigma = -0.5;
    140:   STSetShift(st,sigma);
    141:   STGetShift(st,&sigma);
    142:   PetscPrintf(PETSC_COMM_WORLD,"With shift=%g\n",(double)PetscRealPart(sigma));
    143:   STApply(st,v,w);
    144:   VecView(w,NULL);

    146:   STDestroy(&st);
    147:   MatDestroy(&A);
    148:   MatDestroy(&S);
    149:   VecDestroy(&v);
    150:   VecDestroy(&w);
    151:   SlepcFinalize();
    152:   return 0;
    153: }

    157: static PetscErrorCode MatMult_Shell(Mat S,Vec x,Vec y)
    158: {
    159:   PetscErrorCode    ierr;
    160:   Mat               *A;

    163:   MatShellGetContext(S,&A);
    164:   MatMult(*A,x,y);
    165:   return(0);
    166: }

    170: static PetscErrorCode MatMultTranspose_Shell(Mat S,Vec x,Vec y)
    171: {
    172:   PetscErrorCode    ierr;
    173:   Mat               *A;

    176:   MatShellGetContext(S,&A);
    177:   MatMultTranspose(*A,x,y);
    178:   return(0);
    179: }

    183: static PetscErrorCode MatGetDiagonal_Shell(Mat S,Vec diag)
    184: {
    185:   PetscErrorCode    ierr;
    186:   Mat               *A;

    189:   MatShellGetContext(S,&A);
    190:   MatGetDiagonal(*A,diag);
    191:   return(0);
    192: }

    196: static PetscErrorCode MatDuplicate_Shell(Mat S,MatDuplicateOption op,Mat *M)
    197: {
    199:   Mat            *A;

    202:   MatShellGetContext(S,&A);
    203:   MyShellMatCreate(A,M);
    204:   return(0);
    205: }