Date: 2022-08-09T09:05:26+00:00

Actual source code: test8.c
slepc-3.17.2 2022-08-09
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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: */

     11: static char help[] = "Test BV orthogonalization with selected columns.\n\n";

     13: #include <slepcbv.h>

     15: int main(int argc,char **argv)
     16: {
     17:   BV             X;
     18:   Vec            v,t,z;
     19:   PetscInt       i,j,n=20,k=8;
     20:   PetscViewer    view;
     21:   PetscBool      verbose,*which;
     22:   PetscReal      norm;
     23:   PetscScalar    alpha,*pz;

     25:   SlepcInitialize(&argc,&argv,(char*)0,help);
     26:   PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);
     27:   PetscOptionsGetInt(NULL,NULL,"-k",&k,NULL);
     28:   PetscOptionsHasName(NULL,NULL,"-verbose",&verbose);
     29:   PetscPrintf(PETSC_COMM_WORLD,"Test BV orthogonalization with selected columns of length %" PetscInt_FMT ".\n",n);

     31:   /* Create template vector */
     32:   VecCreate(PETSC_COMM_WORLD,&t);
     33:   VecSetSizes(t,PETSC_DECIDE,n);
     34:   VecSetFromOptions(t);

     36:   /* Create BV object X */
     37:   BVCreate(PETSC_COMM_WORLD,&X);
     38:   PetscObjectSetName((PetscObject)X,"X");
     39:   BVSetSizesFromVec(X,t,k);
     40:   BVSetOrthogonalization(X,BV_ORTHOG_MGS,BV_ORTHOG_REFINE_IFNEEDED,PETSC_DEFAULT,BV_ORTHOG_BLOCK_GS);
     41:   BVSetFromOptions(X);

     43:   /* Set up viewer */
     44:   PetscViewerASCIIGetStdout(PETSC_COMM_WORLD,&view);
     45:   if (verbose) PetscViewerPushFormat(view,PETSC_VIEWER_ASCII_MATLAB);

     47:   /* Fill X entries */
     48:   for (j=0;j<k;j++) {
     49:     BVGetColumn(X,j,&v);
     50:     VecSet(v,0.0);
     51:     for (i=0;i<=n/2;i++) {
     52:       if (i+j<n) {
     53:         alpha = (3.0*i+j-2)/(2*(i+j+1));
     54:         VecSetValue(v,i+j,alpha,INSERT_VALUES);
     55:       }
     56:     }
     57:     VecAssemblyBegin(v);
     58:     VecAssemblyEnd(v);
     59:     BVRestoreColumn(X,j,&v);
     60:   }
     61:   if (verbose) BVView(X,view);

     63:   /* Orthonormalize first k-1 columns */
     64:   for (j=0;j<k-1;j++) {
     65:     BVOrthogonalizeColumn(X,j,NULL,&norm,NULL);
     66:     alpha = 1.0/norm;
     67:     BVScaleColumn(X,j,alpha);
     68:   }
     69:   if (verbose) BVView(X,view);

     71:   /* Select odd columns and orthogonalize last column against those only */
     72:   PetscMalloc1(k,&which);
     73:   for (i=0;i<k;i++) which[i] = (i%2)? PETSC_TRUE: PETSC_FALSE;
     74:   BVOrthogonalizeSomeColumn(X,k-1,which,NULL,NULL,NULL);
     75:   PetscFree(which);
     76:   if (verbose) BVView(X,view);

     78:   /* Check orthogonality */
     79:   PetscPrintf(PETSC_COMM_WORLD,"Orthogonalization coefficients:\n");
     80:   VecCreateSeq(PETSC_COMM_SELF,k-1,&z);
     81:   PetscObjectSetName((PetscObject)z,"z");
     82:   VecGetArray(z,&pz);
     83:   BVDotColumn(X,k-1,pz);
     84:   for (i=0;i<k-1;i++) {
     85:     if (PetscAbsScalar(pz[i])<5.0*PETSC_MACHINE_EPSILON) pz[i]=0.0;
     86:   }
     87:   VecRestoreArray(z,&pz);
     88:   VecView(z,view);
     89:   VecDestroy(&z);

     91:   BVDestroy(&X);
     92:   VecDestroy(&t);
     93:   SlepcFinalize();
     94:   return 0;
     95: }

     97: /*TEST

     99:    testset:
    100:       output_file: output/test8_1.out
    101:       test:
    102:          suffix: 1
    103:          args: -bv_type {{vecs contiguous svec mat}shared output}
    104:       test:
    105:          suffix: 1_cuda
    106:          args: -bv_type svec -vec_type cuda
    107:          requires: cuda
    108:       test:
    109:          suffix: 2
    110:          args: -bv_type {{vecs contiguous svec mat}shared output} -bv_orthog_refine never
    111:          requires: !single
    112:       test:
    113:          suffix: 3
    114:          args: -bv_type {{vecs contiguous svec mat}shared output} -bv_orthog_refine always
    115:       test:
    116:          suffix: 4
    117:          args: -bv_type {{vecs contiguous svec mat}shared output} -bv_orthog_type mgs
    118:       test:
    119:          suffix: 4_cuda
    120:          args: -bv_type svec -vec_type cuda -bv_orthog_type mgs
    121:          requires: cuda

    123: TEST*/