Date: 2022-08-09T09:05:23+00:00

Actual source code: test17.c
slepc-3.17.2 2022-08-09
Report Typos and Errors

      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 DSPEP with complex eigenvalues.\n\n";

     13: #include <slepcds.h>

     15: int main(int argc,char **argv)
     16: {
     17:   DS             ds;
     18:   SlepcSC        sc;
     19:   Mat            X;
     20:   Vec            x0;
     21:   PetscScalar    *K,*M,*wr,*wi;
     22:   PetscReal      re,im,nrm;
     23:   PetscInt       i,n=10,d=2,ld;
     24:   PetscViewer    viewer;
     25:   PetscBool      verbose;

     27:   SlepcInitialize(&argc,&argv,(char*)0,help);
     28:   PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);
     29:   PetscPrintf(PETSC_COMM_WORLD,"Solve a Dense System of type PEP - n=%" PetscInt_FMT ".\n",n);
     30:   PetscOptionsHasName(NULL,NULL,"-verbose",&verbose);

     32:   /* Create DS object */
     33:   DSCreate(PETSC_COMM_WORLD,&ds);
     34:   DSSetType(ds,DSPEP);
     35:   DSSetFromOptions(ds);
     36:   DSPEPSetDegree(ds,d);

     38:   /* Set dimensions */
     39:   ld = n+2;  /* test leading dimension larger than n */
     40:   DSAllocate(ds,ld);
     41:   DSSetDimensions(ds,n,0,0);

     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) PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_MATLAB);

     50:   /* Fill matrices */
     51:   DSGetArray(ds,DS_MAT_E0,&K);
     52:   for (i=0;i<n;i++) K[i+i*ld] = 2.0;
     53:   for (i=1;i<n;i++) {
     54:     K[i+(i-1)*ld] = -1.0;
     55:     K[(i-1)+i*ld] = -1.0;
     56:   }
     57:   DSRestoreArray(ds,DS_MAT_E0,&K);
     58:   DSGetArray(ds,DS_MAT_E2,&M);
     59:   for (i=0;i<n;i++) M[i+i*ld] = 1.0;
     60:   DSRestoreArray(ds,DS_MAT_E2,&M);

     62:   if (verbose) {
     63:     PetscPrintf(PETSC_COMM_WORLD,"Initial - - - - - - - - -\n");
     64:     DSView(ds,viewer);
     65:   }

     67:   /* Solve */
     68:   PetscMalloc2(d*n,&wr,d*n,&wi);
     69:   DSGetSlepcSC(ds,&sc);
     70:   sc->comparison    = SlepcCompareLargestImaginary;
     71:   sc->comparisonctx = NULL;
     72:   sc->map           = NULL;
     73:   sc->mapobj        = NULL;
     74:   DSSolve(ds,wr,wi);
     75:   DSSort(ds,wr,wi,NULL,NULL,NULL);
     76:   if (verbose) {
     77:     PetscPrintf(PETSC_COMM_WORLD,"After solve - - - - - - - - -\n");
     78:     DSView(ds,viewer);
     79:   }

     81:   /* Print eigenvalues */
     82:   PetscPrintf(PETSC_COMM_WORLD,"Computed eigenvalues =\n");
     83:   for (i=0;i<d*n;i++) {
     84: #if defined(PETSC_USE_COMPLEX)
     85:     re = PetscRealPart(wr[i]);
     86:     im = PetscImaginaryPart(wr[i]);
     87: #else
     88:     re = wr[i];
     89:     im = wi[i];
     90: #endif
     91:     if (PetscAbs(im)<1e-10) PetscViewerASCIIPrintf(viewer,"  %.5f\n",(double)re);
     92:     else PetscViewerASCIIPrintf(viewer,"  %.5f%+.5fi\n",(double)re,(double)im);
     93:   }

     95:   /* Eigenvectors */
     96:   DSVectors(ds,DS_MAT_X,NULL,NULL);  /* all eigenvectors */
     97:   DSGetMat(ds,DS_MAT_X,&X);
     98:   MatCreateVecs(X,NULL,&x0);
     99:   MatGetColumnVector(X,x0,1);
    100:   VecNorm(x0,NORM_2,&nrm);
    101:   MatDestroy(&X);
    102:   VecDestroy(&x0);
    103:   PetscPrintf(PETSC_COMM_WORLD,"Norm of 2nd column of X = %.3f\n",(double)nrm);
    104:   if (verbose) {
    105:     PetscPrintf(PETSC_COMM_WORLD,"After vectors - - - - - - - - -\n");
    106:     DSView(ds,viewer);
    107:   }

    109:   PetscFree2(wr,wi);
    110:   DSDestroy(&ds);
    111:   SlepcFinalize();
    112:   return 0;
    113: }

    115: /*TEST

    117:    test:
    118:       suffix: 1
    119:       args: -n 7
    120:       requires: !complex
    121:       filter: sed -e 's/-0.00000/0.00000/'

    123:    test:
    124:       suffix: 1_complex
    125:       args: -n 7
    126:       requires: complex
    127:       filter: sed -e 's/-0.00000/0.00000/'

    129: TEST*/