Date: 2021-02-01T14:41:44+00:00

Actual source code: test1.c
slepc-3.14.2 2021-02-01
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      1: /*
      2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
      3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
      4:    Copyright (c) 2002-2020, 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 DSNHEP.\n\n";

     13: #include <slepcds.h>

     15: int main(int argc,char **argv)
     16: {
     18:   DS             ds;
     19:   SlepcSC        sc;
     20:   DSType         type;
     21:   DSStateType    state;
     22:   PetscScalar    *A,*X,*wr,*wi;
     23:   PetscReal      re,im,rnorm,aux;
     24:   PetscInt       i,j,n=10,ld,method;
     25:   PetscViewer    viewer;
     26:   PetscBool      verbose,extrarow;

     28:   SlepcInitialize(&argc,&argv,(char*)0,help);if (ierr) return ierr;
     29:   PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);
     30:   PetscPrintf(PETSC_COMM_WORLD,"Solve a Dense System of type NHEP - dimension %D.\n",n);
     31:   PetscOptionsHasName(NULL,NULL,"-verbose",&verbose);
     32:   PetscOptionsHasName(NULL,NULL,"-extrarow",&extrarow);

     34:   /* Create DS object */
     35:   DSCreate(PETSC_COMM_WORLD,&ds);
     36:   DSSetType(ds,DSNHEP);
     37:   DSSetFromOptions(ds);
     38:   ld = n+2;  /* test leading dimension larger than n */
     39:   DSAllocate(ds,ld);
     40:   DSSetDimensions(ds,n,0,0,0);
     41:   DSSetExtraRow(ds,extrarow);

     43:   /* Set up viewer */
     44:   PetscViewerASCIIGetStdout(PETSC_COMM_WORLD,&viewer);
     45:   PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_INFO_DETAIL);
     46:   DSView(ds,viewer);
     47:   PetscViewerPopFormat(viewer);
     48:   if (verbose) {
     49:     PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_MATLAB);
     50:   }

     52:   /* Fill with Grcar matrix */
     53:   DSGetArray(ds,DS_MAT_A,&A);
     54:   for (i=1;i<n;i++) A[i+(i-1)*ld]=-1.0;
     55:   for (j=0;j<4;j++) {
     56:     for (i=0;i<n-j;i++) A[i+(i+j)*ld]=1.0;
     57:   }
     58:   if (extrarow) A[n+(n-1)*ld]=-1.0;
     59:   DSRestoreArray(ds,DS_MAT_A,&A);
     60:   DSSetState(ds,DS_STATE_INTERMEDIATE);
     61:   if (verbose) {
     62:     PetscPrintf(PETSC_COMM_WORLD,"Initial - - - - - - - - -\n");
     63:     DSView(ds,viewer);
     64:   }

     66:   /* Solve */
     67:   PetscMalloc2(n,&wr,n,&wi);
     68:   DSGetSlepcSC(ds,&sc);
     69:   sc->comparison    = SlepcCompareLargestMagnitude;
     70:   sc->comparisonctx = NULL;
     71:   sc->map           = NULL;
     72:   sc->mapobj        = NULL;
     73:   DSSolve(ds,wr,wi);
     74:   DSSort(ds,wr,wi,NULL,NULL,NULL);
     75:   if (extrarow) { DSUpdateExtraRow(ds); }

     77:   DSGetType(ds,&type);
     78:   DSGetMethod(ds,&method);
     79:   PetscPrintf(PETSC_COMM_WORLD,"DS of type %s, method used=%d\n",type,method);
     80:   DSGetState(ds,&state);
     81:   PetscPrintf(PETSC_COMM_WORLD,"State after solve: %s\n",DSStateTypes[state]);

     83:   if (verbose) {
     84:     PetscPrintf(PETSC_COMM_WORLD,"After solve - - - - - - - - -\n");
     85:     DSView(ds,viewer);
     86:   }

     88:   /* Print eigenvalues */
     89:   PetscPrintf(PETSC_COMM_WORLD,"Computed eigenvalues =\n");
     90:   for (i=0;i<n;i++) {
     91: #if defined(PETSC_USE_COMPLEX)
     92:     re = PetscRealPart(wr[i]);
     93:     im = PetscImaginaryPart(wr[i]);
     94: #else
     95:     re = wr[i];
     96:     im = wi[i];
     97: #endif
     98:     if (PetscAbs(im)<1e-10) {
     99:       PetscViewerASCIIPrintf(viewer,"  %.5f\n",(double)re);
    100:     } else {
    101:       PetscViewerASCIIPrintf(viewer,"  %.5f%+.5fi\n",(double)re,(double)im);
    102:     }
    103:   }

    105:   /* Eigenvectors */
    106:   j = 2;
    107:   DSVectors(ds,DS_MAT_X,&j,&rnorm);  /* third eigenvector */
    108:   PetscPrintf(PETSC_COMM_WORLD,"Value of rnorm for 3rd vector = %.3f\n",(double)rnorm);
    109:   DSVectors(ds,DS_MAT_X,NULL,NULL);  /* all eigenvectors */
    110:   j = 0;
    111:   rnorm = 0.0;
    112:   DSGetArray(ds,DS_MAT_X,&X);
    113:   for (i=0;i<n;i++) {
    114: #if defined(PETSC_USE_COMPLEX)
    115:     aux = PetscAbsScalar(X[i+j*ld]);
    116: #else
    117:     if (PetscAbs(wi[j])==0.0) aux = PetscAbsScalar(X[i+j*ld]);
    118:     else aux = SlepcAbsEigenvalue(X[i+j*ld],X[i+(j+1)*ld]);
    119: #endif
    120:     rnorm += aux*aux;
    121:   }
    122:   DSRestoreArray(ds,DS_MAT_X,&X);
    123:   rnorm = PetscSqrtReal(rnorm);
    124:   PetscPrintf(PETSC_COMM_WORLD,"Norm of 1st vector = %.3f\n",(double)rnorm);
    125:   if (verbose) {
    126:     PetscPrintf(PETSC_COMM_WORLD,"After vectors - - - - - - - - -\n");
    127:     DSView(ds,viewer);
    128:   }

    130:   PetscFree2(wr,wi);
    131:   DSDestroy(&ds);
    132:   SlepcFinalize();
    133:   return ierr;
    134: }

    136: /*TEST

    138:    test:
    139:       suffix: 1
    140:       filter: sed -e "s/[+-]\([0-9]\.[0-9]*i\)/+-\\1/"
    141:       requires: !single

    143: TEST*/