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

Actual source code: test6.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 BV orthogonalization functions with constraints.\n\n";

     24: #include <slepcbv.h>

     28: int main(int argc,char **argv)
     29: {
     31:   BV             X;
     32:   Mat            M;
     33:   Vec            v,t,*C;
     34:   PetscInt       i,j,n=20,k=8,nc=2;
     35:   PetscViewer    view;
     36:   PetscBool      verbose;
     37:   PetscReal      norm;
     38:   PetscScalar    alpha;

     40:   SlepcInitialize(&argc,&argv,(char*)0,help);
     41:   PetscOptionsGetInt(NULL,"-n",&n,NULL);
     42:   PetscOptionsGetInt(NULL,"-k",&k,NULL);
     43:   PetscOptionsGetInt(NULL,"-nc",&nc,NULL);
     44:   PetscOptionsHasName(NULL,"-verbose",&verbose);
     45:   PetscPrintf(PETSC_COMM_WORLD,"Test BV orthogonalization with %D columns + %D constraints, of length %D.\n",k,nc,n);

     47:   /* Create template vector */
     48:   VecCreate(PETSC_COMM_WORLD,&t);
     49:   VecSetSizes(t,PETSC_DECIDE,n);
     50:   VecSetFromOptions(t);

     52:   /* Create BV object X */
     53:   BVCreate(PETSC_COMM_WORLD,&X);
     54:   PetscObjectSetName((PetscObject)X,"X");
     55:   BVSetSizesFromVec(X,t,k);
     56:   BVSetFromOptions(X);

     58:   /* Generate constraints and attach them to X */
     59:   if (nc>0) {
     60:     VecDuplicateVecs(t,nc,&C);
     61:     for (j=0;j<nc;j++) {
     62:       for (i=0;i<=j;i++) {
     63:         VecSetValue(C[j],i,1.0,INSERT_VALUES);
     64:       }
     65:       VecAssemblyBegin(C[j]);
     66:       VecAssemblyEnd(C[j]);
     67:     }
     68:     BVInsertConstraints(X,&nc,C);
     69:     VecDestroyVecs(nc,&C);
     70:   }

     72:   /* Set up viewer */
     73:   PetscViewerASCIIGetStdout(PETSC_COMM_WORLD,&view);
     74:   if (verbose) {
     75:     PetscViewerPushFormat(view,PETSC_VIEWER_ASCII_MATLAB);
     76:   }

     78:   /* Fill X entries */
     79:   for (j=0;j<k;j++) {
     80:     BVGetColumn(X,j,&v);
     81:     VecSet(v,0.0);
     82:     for (i=0;i<=n/2;i++) {
     83:       if (i+j<n) {
     84:         alpha = (3.0*i+j-2)/(2*(i+j+1));
     85:         VecSetValue(v,i+j,alpha,INSERT_VALUES);
     86:       }
     87:     }
     88:     VecAssemblyBegin(v);
     89:     VecAssemblyEnd(v);
     90:     BVRestoreColumn(X,j,&v);
     91:   }
     92:   if (verbose) {
     93:     BVView(X,view);
     94:   }

     96:   /* Test BVOrthogonalizeColumn */
     97:   for (j=0;j<k;j++) {
     98:     BVOrthogonalizeColumn(X,j,NULL,&norm,NULL);
     99:     alpha = 1.0/norm;
    100:     BVScaleColumn(X,j,alpha);
    101:   }
    102:   if (verbose) {
    103:     BVView(X,view);
    104:   }

    106:   /* Check orthogonality */
    107:   MatCreateSeqDense(PETSC_COMM_SELF,k,k,NULL,&M);
    108:   BVDot(X,X,M);
    109:   MatShift(M,-1.0);
    110:   MatNorm(M,NORM_1,&norm);
    111:   if (norm<100*PETSC_MACHINE_EPSILON) {
    112:     PetscPrintf(PETSC_COMM_WORLD,"Level of orthogonality < 100*eps\n");
    113:   } else {
    114:     PetscPrintf(PETSC_COMM_WORLD,"Level of orthogonality: %g\n",(double)norm);
    115:   }

    117:   MatDestroy(&M);
    118:   BVDestroy(&X);
    119:   VecDestroy(&t);
    120:   SlepcFinalize();
    121:   return 0;
    122: }