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 DSGHIEP 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,*s,re,im;
 20:   PetscScalar    *eigr,*eigi;
 21:   PetscInt       i,n=10,l=2,k=5,ld;
 22:   PetscViewer    viewer;
 23:   PetscBool      verbose;

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

 34:   /* Create DS object */
 35:   PetscCall(DSCreate(PETSC_COMM_WORLD,&ds));
 36:   PetscCall(DSSetType(ds,DSGHIEP));
 37:   PetscCall(DSSetFromOptions(ds));
 38:   ld = n+2;  /* test leading dimension larger than n */
 39:   PetscCall(DSAllocate(ds,ld));
 40:   PetscCall(DSSetDimensions(ds,n,l,k));
 41:   PetscCall(DSSetCompact(ds,PETSC_TRUE));

 43:   /* Set up viewer */
 44:   PetscCall(PetscViewerASCIIGetStdout(PETSC_COMM_WORLD,&viewer));
 45:   PetscCall(PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_INFO_DETAIL));
 46:   PetscCall(DSView(ds,viewer));
 47:   PetscCall(PetscViewerPopFormat(viewer));
 48:   PetscCall(PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_MATLAB));

 50:   /* Fill arrow-tridiagonal matrix */
 51:   PetscCall(DSGetArrayReal(ds,DS_MAT_T,&T));
 52:   PetscCall(DSGetArrayReal(ds,DS_MAT_D,&s));
 53:   for (i=0;i<n;i++) T[i] = (PetscReal)(i+1);
 54:   for (i=k;i<n-1;i++) T[i+ld] = 1.0;
 55:   for (i=l;i<k;i++) T[i+2*ld] = 1.0;
 56:   T[2*ld+l+1] = -7; T[ld+k+1] = -7;
 57:   /* Signature matrix */
 58:   for (i=0;i<n;i++) s[i] = 1.0;
 59:   s[l+1] = -1.0;
 60:   s[k+1] = -1.0;
 61:   PetscCall(DSRestoreArrayReal(ds,DS_MAT_T,&T));
 62:   PetscCall(DSRestoreArrayReal(ds,DS_MAT_D,&s));
 63:   if (l==0 && k==0) PetscCall(DSSetState(ds,DS_STATE_INTERMEDIATE));
 64:   else PetscCall(DSSetState(ds,DS_STATE_RAW));
 65:   PetscCall(PetscPrintf(PETSC_COMM_WORLD,"Initial - - - - - - - - -\n"));
 66:   PetscCall(DSView(ds,viewer));

 68:   /* Solve */
 69:   PetscCall(PetscCalloc2(n,&eigr,n,&eigi));
 70:   PetscCall(DSGetSlepcSC(ds,&sc));
 71:   sc->comparison    = SlepcCompareLargestMagnitude;
 72:   sc->comparisonctx = NULL;
 73:   sc->map           = NULL;
 74:   sc->mapobj        = NULL;
 75:   PetscCall(DSSolve(ds,eigr,eigi));
 76:   PetscCall(DSSort(ds,eigr,eigi,NULL,NULL,NULL));
 77:   if (verbose) {
 78:     PetscCall(PetscPrintf(PETSC_COMM_WORLD,"After solve - - - - - - - - -\n"));
 79:     PetscCall(DSView(ds,viewer));
 80:   }

 82:   /* Print eigenvalues */
 83:   PetscCall(PetscPrintf(PETSC_COMM_WORLD,"Computed eigenvalues =\n"));
 84:   for (i=0;i<n;i++) {
 85: #if defined(PETSC_USE_COMPLEX)
 86:     re = PetscRealPart(eigr[i]);
 87:     im = PetscImaginaryPart(eigr[i]);
 88: #else
 89:     re = eigr[i];
 90:     im = eigi[i];
 91: #endif
 92:     if (PetscAbs(im)<1e-10) PetscCall(PetscViewerASCIIPrintf(viewer,"  %.5f\n",(double)re));
 93:     else PetscCall(PetscViewerASCIIPrintf(viewer,"  %.5f%+.5fi\n",(double)re,(double)im));
 94:   }
 95:   PetscCall(PetscFree2(eigr,eigi));
 96:   PetscCall(DSDestroy(&ds));
 97:   PetscCall(SlepcFinalize());
 98:   return 0;
 99: }

101: /*TEST

103:    test:
104:       suffix: 1
105:       requires: !single
106:       args: -ds_method {{0 1 2}}
107:       filter: grep -v "solving the problem"

109:    test:
110:       suffix: 2
111:       args: -n 5 -k 4 -l 4 -ds_method {{0 1 2}}
112:       filter: grep -v "solving the problem"

114: TEST*/