Date: 2017-05-17T08:24:52+00:00

Actual source code: test1.c
slepc-3.7.4 2017-05-17
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      1: /*
      2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
      3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
      4:    Copyright (c) 2002-2016, Universitat Politecnica de Valencia, Spain

      6:    This file is part of SLEPc.

      8:    SLEPc is free software: you can redistribute it and/or modify it under  the
      9:    terms of version 3 of the GNU Lesser General Public License as published by
     10:    the Free Software Foundation.

     12:    SLEPc  is  distributed in the hope that it will be useful, but WITHOUT  ANY
     13:    WARRANTY;  without even the implied warranty of MERCHANTABILITY or  FITNESS
     14:    FOR  A  PARTICULAR PURPOSE. See the GNU Lesser General Public  License  for
     15:    more details.

     17:    You  should have received a copy of the GNU Lesser General  Public  License
     18:    along with SLEPc. If not, see <http://www.gnu.org/licenses/>.
     19:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     20: */

     22: static char help[] = "Test DSNHEP.\n\n";

     24: #include <slepcds.h>

     28: int main(int argc,char **argv)
     29: {
     31:   DS             ds;
     32:   SlepcSC        sc;
     33:   PetscScalar    *A,*X,*wr,*wi;
     34:   PetscReal      re,im,rnorm,aux;
     35:   PetscInt       i,j,n=10,ld;
     36:   PetscViewer    viewer;
     37:   PetscBool      verbose,extrarow;

     39:   SlepcInitialize(&argc,&argv,(char*)0,help);
     40:   PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);
     41:   PetscPrintf(PETSC_COMM_WORLD,"Solve a Dense System of type NHEP - dimension %D.\n",n);
     42:   PetscOptionsHasName(NULL,NULL,"-verbose",&verbose);
     43:   PetscOptionsHasName(NULL,NULL,"-extrarow",&extrarow);

     45:   /* Create DS object */
     46:   DSCreate(PETSC_COMM_WORLD,&ds);
     47:   DSSetType(ds,DSNHEP);
     48:   DSSetFromOptions(ds);
     49:   ld = n+2;  /* test leading dimension larger than n */
     50:   DSAllocate(ds,ld);
     51:   DSSetDimensions(ds,n,0,0,0);
     52:   DSSetExtraRow(ds,extrarow);

     54:   /* Set up viewer */
     55:   PetscViewerASCIIGetStdout(PETSC_COMM_WORLD,&viewer);
     56:   PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_INFO_DETAIL);
     57:   DSView(ds,viewer);
     58:   PetscViewerPopFormat(viewer);
     59:   if (verbose) {
     60:     PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_MATLAB);
     61:   }

     63:   /* Fill with Grcar matrix */
     64:   DSGetArray(ds,DS_MAT_A,&A);
     65:   for (i=1;i<n;i++) A[i+(i-1)*ld]=-1.0;
     66:   for (j=0;j<4;j++) {
     67:     for (i=0;i<n-j;i++) A[i+(i+j)*ld]=1.0;
     68:   }
     69:   if (extrarow) A[n+(n-1)*ld]=-1.0;
     70:   DSRestoreArray(ds,DS_MAT_A,&A);
     71:   DSSetState(ds,DS_STATE_INTERMEDIATE);
     72:   if (verbose) {
     73:     PetscPrintf(PETSC_COMM_WORLD,"Initial - - - - - - - - -\n");
     74:     DSView(ds,viewer);
     75:   }

     77:   /* Solve */
     78:   PetscMalloc2(n,&wr,n,&wi);
     79:   DSGetSlepcSC(ds,&sc);
     80:   sc->comparison    = SlepcCompareLargestMagnitude;
     81:   sc->comparisonctx = NULL;
     82:   sc->map           = NULL;
     83:   sc->mapobj        = NULL;
     84:   DSSolve(ds,wr,wi);
     85:   DSSort(ds,wr,wi,NULL,NULL,NULL);
     86:   if (extrarow) { DSUpdateExtraRow(ds); }
     87:   if (verbose) {
     88:     PetscPrintf(PETSC_COMM_WORLD,"After solve - - - - - - - - -\n");
     89:     DSView(ds,viewer);
     90:   }

     92:   /* Print eigenvalues */
     93:   PetscPrintf(PETSC_COMM_WORLD,"Computed eigenvalues =\n");
     94:   for (i=0;i<n;i++) {
     95: #if defined(PETSC_USE_COMPLEX)
     96:     re = PetscRealPart(wr[i]);
     97:     im = PetscImaginaryPart(wr[i]);
     98: #else
     99:     re = wr[i];
    100:     im = wi[i];
    101: #endif
    102:     if (PetscAbs(im)<1e-10) {
    103:       PetscViewerASCIIPrintf(viewer,"  %.5f\n",(double)re);
    104:     } else {
    105:       PetscViewerASCIIPrintf(viewer,"  %.5f%+.5fi\n",(double)re,(double)im);
    106:     }
    107:   }

    109:   /* Eigenvectors */
    110:   j = 2;
    111:   DSVectors(ds,DS_MAT_X,&j,&rnorm);  /* third eigenvector */
    112:   PetscPrintf(PETSC_COMM_WORLD,"Value of rnorm for 3rd vector = %.3f\n",(double)rnorm);
    113:   DSVectors(ds,DS_MAT_X,NULL,NULL);  /* all eigenvectors */
    114:   j = 0;
    115:   rnorm = 0.0;
    116:   DSGetArray(ds,DS_MAT_X,&X);
    117:   for (i=0;i<n;i++) {
    118: #if defined(PETSC_USE_COMPLEX)
    119:     aux = PetscAbsScalar(X[i+j*ld]);
    120: #else
    121:     if (PetscAbs(wi[j])==0.0) aux = PetscAbsScalar(X[i+j*ld]);
    122:     else aux = SlepcAbsEigenvalue(X[i+j*ld],X[i+(j+1)*ld]);
    123: #endif
    124:     rnorm += aux*aux;
    125:   }
    126:   DSRestoreArray(ds,DS_MAT_X,&X);
    127:   rnorm = PetscSqrtReal(rnorm);
    128:   PetscPrintf(PETSC_COMM_WORLD,"Norm of 1st vector = %.3f\n",(double)rnorm);
    129:   if (verbose) {
    130:     PetscPrintf(PETSC_COMM_WORLD,"After vectors - - - - - - - - -\n");
    131:     DSView(ds,viewer);
    132:   }

    134:   PetscFree2(wr,wi);
    135:   DSDestroy(&ds);
    136:   SlepcFinalize();
    137:   return ierr;
    138: }