Date: 2017-05-17T08:24:53+00:00

Actual source code: test4.c
slepc-3.7.4 2017-05-17
Report Typos and Errors

      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 DSGNHEP.\n\n";

     24: #include <slepcds.h>

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

     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 GNHEP - dimension %D.\n",n);
     42:   PetscOptionsHasName(NULL,NULL,"-verbose",&verbose);

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

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

     61:   /* Fill A with Grcar matrix */
     62:   DSGetArray(ds,DS_MAT_A,&A);
     63:   PetscMemzero(A,sizeof(PetscScalar)*ld*n);
     64:   for (i=1;i<n;i++) A[i+(i-1)*ld]=-1.0;
     65:   for (j=0;j<4;j++) {
     66:     for (i=0;i<n-j;i++) A[i+(i+j)*ld]=1.0;
     67:   }
     68:   DSRestoreArray(ds,DS_MAT_A,&A);
     69:   /* Fill B with an identity matrix */
     70:   DSGetArray(ds,DS_MAT_B,&B);
     71:   PetscMemzero(B,sizeof(PetscScalar)*ld*n);
     72:   for (i=0;i<n;i++) B[i+i*ld]=1.0;
     73:   DSRestoreArray(ds,DS_MAT_B,&B);

     75:   if (verbose) {
     76:     PetscPrintf(PETSC_COMM_WORLD,"Initial - - - - - - - - -\n");
     77:     DSView(ds,viewer);
     78:   }

     80:   /* Solve */
     81:   PetscMalloc2(n,&wr,n,&wi);
     82:   DSGetSlepcSC(ds,&sc);
     83:   sc->comparison    = SlepcCompareLargestMagnitude;
     84:   sc->comparisonctx = NULL;
     85:   sc->map           = NULL;
     86:   sc->mapobj        = NULL;
     87:   DSSolve(ds,wr,wi);
     88:   DSSort(ds,wr,wi,NULL,NULL,NULL);
     89:   if (verbose) {
     90:     PetscPrintf(PETSC_COMM_WORLD,"After solve - - - - - - - - -\n");
     91:     DSView(ds,viewer);
     92:   }

     94:   /* Print eigenvalues */
     95:   PetscPrintf(PETSC_COMM_WORLD,"Computed eigenvalues =\n");
     96:   for (i=0;i<n;i++) {
     97: #if defined(PETSC_USE_COMPLEX)
     98:     re = PetscRealPart(wr[i]);
     99:     im = PetscImaginaryPart(wr[i]);
    100: #else
    101:     re = wr[i];
    102:     im = wi[i];
    103: #endif
    104:     if (PetscAbs(im)<1e-10) {
    105:       PetscViewerASCIIPrintf(viewer,"  %.5f\n",(double)re);
    106:     } else {
    107:       PetscViewerASCIIPrintf(viewer,"  %.5f%+.5fi\n",(double)re,(double)im);
    108:     }
    109:   }

    111:   /* Eigenvectors */
    112:   j = 2;
    113:   DSVectors(ds,DS_MAT_X,&j,&rnorm);  /* third eigenvector */
    114:   PetscPrintf(PETSC_COMM_WORLD,"Value of rnorm for 3rd vector = %.3f\n",(double)rnorm);
    115:   DSVectors(ds,DS_MAT_X,NULL,NULL);  /* all eigenvectors */
    116:   j = 0;
    117:   rnorm = 0.0;
    118:   DSGetArray(ds,DS_MAT_X,&X);
    119:   for (i=0;i<n;i++) {
    120: #if defined(PETSC_USE_COMPLEX)
    121:     aux = PetscAbsScalar(X[i+j*ld]);
    122: #else
    123:     if (PetscAbs(wi[j])==0.0) aux = PetscAbsScalar(X[i+j*ld]);
    124:     else aux = SlepcAbsEigenvalue(X[i+j*ld],X[i+(j+1)*ld]);
    125: #endif
    126:     rnorm += aux*aux;
    127:   }
    128:   DSRestoreArray(ds,DS_MAT_X,&X);
    129:   rnorm = PetscSqrtReal(rnorm);
    130:   PetscPrintf(PETSC_COMM_WORLD,"Norm of 1st vector = %.3f\n",(double)rnorm);
    131:   if (verbose) {
    132:     PetscPrintf(PETSC_COMM_WORLD,"After vectors - - - - - - - - -\n");
    133:     DSView(ds,viewer);
    134:   }

    136:   PetscFree2(wr,wi);
    137:   DSDestroy(&ds);
    138:   SlepcFinalize();
    139:   return ierr;
    140: }