Actual source code: test8.c

slepc-3.18.3 2023-03-24
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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;

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

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

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

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

 48:   /* Fill X entries */
 49:   for (j=0;j<k;j++) {
 50:     BVGetColumn(X,j,&v);
 51:     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:         VecSetValue(v,i+j,alpha,INSERT_VALUES);
 56:       }
 57:     }
 58:     VecAssemblyBegin(v);
 59:     VecAssemblyEnd(v);
 60:     BVRestoreColumn(X,j,&v);
 61:   }
 62:   if (verbose) BVView(X,view);

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

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

 79:   /* Check orthogonality */
 80:   PetscPrintf(PETSC_COMM_WORLD,"Orthogonalization coefficients:\n");
 81:   VecCreateSeq(PETSC_COMM_SELF,k-1,&z);
 82:   PetscObjectSetName((PetscObject)z,"z");
 83:   VecGetArray(z,&pz);
 84:   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:   VecRestoreArray(z,&pz);
 89:   VecView(z,view);
 90:   VecDestroy(&z);

 92:   BVDestroy(&X);
 93:   VecDestroy(&t);
 94:   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 -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 -vec_type cuda -bv_orthog_type mgs
122:          requires: cuda

124: TEST*/