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

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

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

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

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

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

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

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

 92:   PetscCall(BVDestroy(&X));
 93:   PetscCall(VecDestroy(&t));
 94:   PetscCall(SlepcFinalize());
 95:   return 0;
 96: }

 98: /*TEST

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

124: TEST*/