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 DSHSVD with compact storage.\n\n";

 13: #include <slepcds.h>

 15: int main(int argc,char **argv)
 16: {
 17:   DS             ds;
 18:   SlepcSC        sc;
 19:   PetscReal      *T,*D,sigma;
 20:   PetscScalar    *U,*w,d;
 21:   PetscInt       i,n=10,m,l=2,k=5,p=1,ld;
 22:   PetscViewer    viewer;
 23:   PetscBool      verbose,extrarow,reorthog,flg;

 25:   PetscFunctionBeginUser;
 26:   PetscCall(SlepcInitialize(&argc,&argv,NULL,help));
 27:   PetscCall(PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL));
 28:   m = n;
 29:   PetscCall(PetscPrintf(PETSC_COMM_WORLD,"Solve a Dense System of type HSVD with compact storage - dimension %" PetscInt_FMT "x%" PetscInt_FMT ".\n",n,m));
 30:   PetscCall(PetscOptionsGetInt(NULL,NULL,"-l",&l,NULL));
 31:   PetscCall(PetscOptionsGetInt(NULL,NULL,"-k",&k,NULL));
 32:   PetscCall(PetscOptionsGetInt(NULL,NULL,"-p",&p,NULL));
 33:   PetscCheck(l<=n && k<=n && l<=k && p>=0 && p<=n-l,PETSC_COMM_WORLD,PETSC_ERR_USER_INPUT,"Wrong value of dimensions");
 34:   PetscCall(PetscOptionsHasName(NULL,NULL,"-verbose",&verbose));
 35:   PetscCall(PetscOptionsHasName(NULL,NULL,"-extrarow",&extrarow));
 36:   PetscCall(PetscOptionsHasName(NULL,NULL,"-reorthog",&reorthog));

 38:   /* Create DS object */
 39:   PetscCall(DSCreate(PETSC_COMM_WORLD,&ds));
 40:   PetscCall(DSSetType(ds,DSHSVD));
 41:   PetscCall(DSSetFromOptions(ds));
 42:   ld = n+2;  /* test leading dimension larger than n */
 43:   PetscCall(DSAllocate(ds,ld));
 44:   PetscCall(DSSetDimensions(ds,n,l,k));
 45:   PetscCall(DSHSVDSetDimensions(ds,m));
 46:   PetscCall(DSSetCompact(ds,PETSC_TRUE));
 47:   PetscCall(DSSetExtraRow(ds,extrarow));
 48:   PetscCall(DSHSVDSetReorthogonalize(ds,reorthog));
 49:   PetscCall(DSHSVDGetReorthogonalize(ds,&flg));
 50:   if (flg) PetscCall(PetscPrintf(PETSC_COMM_WORLD,"reorthogonalizing\n"));

 52:   /* Set up viewer */
 53:   PetscCall(PetscViewerASCIIGetStdout(PETSC_COMM_WORLD,&viewer));
 54:   PetscCall(PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_INFO_DETAIL));
 55:   PetscCall(DSView(ds,viewer));
 56:   PetscCall(PetscViewerPopFormat(viewer));
 57:   PetscCall(PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_MATLAB));

 59:   /* Fill upper arrow-bidiagonal matrix and signature matrix */
 60:   PetscCall(DSGetArrayReal(ds,DS_MAT_T,&T));
 61:   for (i=0;i<n;i++) T[i] = (PetscReal)(i+1);
 62:   for (i=l;i<n-1;i++) T[i+ld] = 1.0;
 63:   if (extrarow) T[n-1+ld] = 1.0;
 64:   PetscCall(DSRestoreArrayReal(ds,DS_MAT_T,&T));
 65:   PetscCall(DSGetArrayReal(ds,DS_MAT_D,&D));
 66:   for (i=0;i<n;i++) D[i] = (i>=l && i<l+p)? -1.0: 1.0;
 67:   PetscCall(DSRestoreArrayReal(ds,DS_MAT_D,&D));
 68:   if (l==0 && k==0) PetscCall(DSSetState(ds,DS_STATE_INTERMEDIATE));
 69:   else PetscCall(DSSetState(ds,DS_STATE_RAW));
 70:   PetscCall(PetscPrintf(PETSC_COMM_WORLD,"Initial - - - - - - - - -\n"));
 71:   PetscCall(DSView(ds,viewer));

 73:   /* Solve */
 74:   PetscCall(PetscMalloc1(n,&w));
 75:   PetscCall(DSGetSlepcSC(ds,&sc));
 76:   sc->comparison    = SlepcCompareLargestReal;
 77:   sc->comparisonctx = NULL;
 78:   sc->map           = NULL;
 79:   sc->mapobj        = NULL;
 80:   PetscCall(DSSolve(ds,w,NULL));
 81:   PetscCall(DSSort(ds,w,NULL,NULL,NULL,NULL));
 82:   if (extrarow) PetscCall(DSUpdateExtraRow(ds));
 83:   if (verbose) {
 84:     PetscCall(PetscPrintf(PETSC_COMM_WORLD,"After solve - - - - - - - - -\n"));
 85:     PetscCall(DSView(ds,viewer));
 86:   }

 88:   /* Print singular values */
 89:   PetscCall(PetscPrintf(PETSC_COMM_WORLD,"Computed singular values =\n"));
 90:   for (i=0;i<n;i++) {
 91:     sigma = PetscRealPart(w[i]);
 92:     PetscCall(PetscViewerASCIIPrintf(viewer,"  %.5f\n",(double)sigma));
 93:   }

 95:   if (extrarow) {
 96:     /* Check that extra row is correct */
 97:     PetscCall(DSGetArrayReal(ds,DS_MAT_T,&T));
 98:     PetscCall(DSGetArray(ds,DS_MAT_U,&U));
 99:     PetscCall(DSGetArrayReal(ds,DS_MAT_D,&D));
100:     d = 0.0;
101:     for (i=l;i<n;i++) d += T[i+ld]-D[i]*U[n-1+i*ld];
102:     if (PetscAbsScalar(d)>10*PETSC_MACHINE_EPSILON) PetscCall(PetscPrintf(PETSC_COMM_WORLD,"Warning: there is a mismatch in the extra row of %g\n",(double)PetscAbsScalar(d)));
103:     PetscCall(DSRestoreArrayReal(ds,DS_MAT_T,&T));
104:     PetscCall(DSRestoreArray(ds,DS_MAT_U,&U));
105:     PetscCall(DSRestoreArrayReal(ds,DS_MAT_D,&D));
106:   }
107:   PetscCall(PetscFree(w));
108:   PetscCall(DSDestroy(&ds));
109:   PetscCall(SlepcFinalize());
110:   return 0;
111: }

113: /*TEST

115:    test:
116:       suffix: 1
117:       requires: !single

119:    test:
120:       args: -l 0 -k 0
121:       suffix: 2
122:       requires: !single

124:    test:
125:       args: -extrarow -reorthog {{0 1}}
126:       suffix: 3
127:       requires: !single
128:       filter: grep -v reorthogonalizing

130: TEST*/