Date: 2016-03-29T14:57:32+00:00

Actual source code: test7.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 multiplication of a Mat times a BV.\n\n";

     24: #include <slepcbv.h>

     28: int main(int argc,char **argv)
     29: {
     31:   Vec            t,v;
     32:   Mat            B;
     33:   BV             X,Y,Z,Zcopy;
     34:   PetscInt       i,j,n=10,k=5,Istart,Iend;
     35:   PetscScalar    *pZ;
     36:   PetscReal      norm;
     37:   PetscViewer    view;
     38:   PetscBool      verbose;

     40:   SlepcInitialize(&argc,&argv,(char*)0,help);
     41:   PetscOptionsGetInt(NULL,"-n",&n,NULL);
     42:   PetscOptionsGetInt(NULL,"-k",&k,NULL);
     43:   PetscOptionsHasName(NULL,"-verbose",&verbose);
     44:   PetscPrintf(PETSC_COMM_WORLD,"Test BVMatMult (n=%D, k=%D).\n",n,k);

     46:   /* Create Laplacian matrix */
     47:   MatCreate(PETSC_COMM_WORLD,&B);
     48:   MatSetSizes(B,PETSC_DECIDE,PETSC_DECIDE,n,n);
     49:   MatSetFromOptions(B);
     50:   MatSetUp(B);
     51:   PetscObjectSetName((PetscObject)B,"B");

     53:   MatGetOwnershipRange(B,&Istart,&Iend);
     54:   for (i=Istart;i<Iend;i++) {
     55:     if (i>0) { MatSetValue(B,i,i-1,-1.0,INSERT_VALUES); }
     56:     if (i<n-1) { MatSetValue(B,i,i+1,-1.0,INSERT_VALUES); }
     57:     MatSetValue(B,i,i,2.0,INSERT_VALUES);
     58:   }
     59:   MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);
     60:   MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);
     61:   MatCreateVecs(B,&t,NULL);

     63:   /* Create BV object X */
     64:   BVCreate(PETSC_COMM_WORLD,&X);
     65:   PetscObjectSetName((PetscObject)X,"X");
     66:   BVSetSizesFromVec(X,t,k);
     67:   BVSetFromOptions(X);

     69:   /* Set up viewer */
     70:   PetscViewerASCIIGetStdout(PETSC_COMM_WORLD,&view);
     71:   if (verbose) {
     72:     PetscViewerPushFormat(view,PETSC_VIEWER_ASCII_MATLAB);
     73:   }

     75:   /* Fill X entries */
     76:   for (j=0;j<k;j++) {
     77:     BVGetColumn(X,j,&v);
     78:     VecSet(v,0.0);
     79:     for (i=Istart;i<PetscMin(j+1,Iend);i++) {
     80:       VecSetValue(v,i,1.0,INSERT_VALUES);
     81:     }
     82:     VecAssemblyBegin(v);
     83:     VecAssemblyEnd(v);
     84:     BVRestoreColumn(X,j,&v);
     85:   }
     86:   if (verbose) {
     87:     MatView(B,view);
     88:     BVView(X,view);
     89:   }

     91:   /* Create BV object Y */
     92:   BVDuplicateResize(X,k+4,&Y);
     93:   PetscObjectSetName((PetscObject)Y,"Y");
     94:   BVSetActiveColumns(Y,2,k+2);

     96:   /* Test BVMatMult */
     97:   BVMatMult(X,B,Y);
     98:   if (verbose) {
     99:     BVView(Y,view);
    100:   }

    102:   /* Create BV object Z */
    103:   BVDuplicate(X,&Z);
    104:   PetscObjectSetName((PetscObject)Z,"Z");

    106:   /* Fill Z entries */
    107:   for (j=0;j<k;j++) {
    108:     BVGetColumn(Z,j,&v);
    109:     VecSet(v,0.0);
    110:     if (!Istart) { VecSetValue(v,0,1.0,ADD_VALUES); }
    111:     if (j<n && j>=Istart && j<Iend) { VecSetValue(v,j,1.0,ADD_VALUES); }
    112:     if (j+1<n && j>=Istart && j<Iend) { VecSetValue(v,j+1,-1.0,ADD_VALUES); }
    113:     VecAssemblyBegin(v);
    114:     VecAssemblyEnd(v);
    115:     BVRestoreColumn(Z,j,&v);
    116:   }
    117:   if (verbose) {
    118:     BVView(Z,view);
    119:   }

    121:   /* Save a copy of Z */
    122:   BVDuplicate(Z,&Zcopy);
    123:   BVCopy(Z,Zcopy);

    125:   /* Test BVAXPY, check result of previous operations */
    126:   BVAXPY(Z,-1.0,Y);
    127:   BVNorm(Z,NORM_FROBENIUS,&norm);
    128:   PetscPrintf(PETSC_COMM_WORLD,"Norm of error: %g\n",(double)norm);

    130:   /* Test BVMatMultColumn, multiply Y(:,2), result in Y(:,3) */
    131:   BVMatMultColumn(Y,B,2);
    132:   if (verbose) {
    133:     BVView(Y,view);
    134:   }

    136:   /* Test BVGetArray, modify Z to match Y */
    137:   BVCopy(Zcopy,Z);
    138:   BVGetArray(Z,&pZ);
    139:   if (Istart==0) {
    140:     if (Iend<3) SETERRQ(PETSC_COMM_SELF,1,"First process must have at least 3 rows");
    141:     pZ[Iend]   = 5.0;   /* modify 3 first entries of second column */
    142:     pZ[Iend+1] = -4.0;
    143:     pZ[Iend+2] = 1.0;
    144:   }
    145:   BVRestoreArray(Z,&pZ);
    146:   if (verbose) {
    147:     BVView(Z,view);
    148:   }

    150:   /* Check result again with BVAXPY */
    151:   BVAXPY(Z,-1.0,Y);
    152:   BVNorm(Z,NORM_FROBENIUS,&norm);
    153:   PetscPrintf(PETSC_COMM_WORLD,"Norm of error: %g\n",(double)norm);

    155:   BVDestroy(&X);
    156:   BVDestroy(&Y);
    157:   BVDestroy(&Z);
    158:   BVDestroy(&Zcopy);
    159:   MatDestroy(&B);
    160:   VecDestroy(&t);
    161:   SlepcFinalize();
    162:   return 0;
    163: }