Date: 2021-02-01T14:41:45+00:00

Actual source code: test15.c
slepc-3.14.2 2021-02-01
Report Typos and Errors

      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 DSPEP.\n\n";

     13: #include <slepcds.h>

     15: int main(int argc,char **argv)
     16: {
     18:   DS             ds;
     19:   SlepcSC        sc;
     20:   Mat            X;
     21:   Vec            x0;
     22:   PetscScalar    *K,*C,*M,*wr,*wi,z=1.0;
     23:   PetscReal      re,im,nrm,*pbc;
     24:   PetscInt       i,j,n=10,d=2,ld;
     25:   PetscViewer    viewer;
     26:   PetscBool      verbose;

     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 PEP - n=%D.\n",n);
     31:   PetscOptionsHasName(NULL,NULL,"-verbose",&verbose);

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

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

     44:   /* Set up viewer */
     45:   PetscViewerASCIIGetStdout(PETSC_COMM_WORLD,&viewer);
     46:   PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_INFO_DETAIL);
     47:   DSView(ds,viewer);
     48:   PetscViewerPopFormat(viewer);
     49:   if (verbose) {
     50:     PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_MATLAB);
     51:   }

     53:   /* Fill matrices */
     54:   DSGetArray(ds,DS_MAT_E0,&K);
     55:   for (i=0;i<n-1;i++) K[i+i*ld] = 2.0*n;
     56:   K[n-1+(n-1)*ld] = 1.0*n;
     57:   for (i=1;i<n;i++) {
     58:     K[i+(i-1)*ld] = -1.0*n;
     59:     K[(i-1)+i*ld] = -1.0*n;
     60:   }
     61:   DSRestoreArray(ds,DS_MAT_E0,&K);
     62:   DSGetArray(ds,DS_MAT_E1,&C);
     63:   C[n-1+(n-1)*ld] = 2.0*PETSC_PI/z;
     64:   DSRestoreArray(ds,DS_MAT_E1,&C);
     65:   DSGetArray(ds,DS_MAT_E2,&M);
     66:   for (i=0;i<n-1;i++) M[i+i*ld] = -4.0*PETSC_PI*PETSC_PI/n;
     67:   M[i+i*ld] = -2.0*PETSC_PI*PETSC_PI/n;
     68:   DSRestoreArray(ds,DS_MAT_E2,&M);

     70:   if (verbose) {
     71:     PetscPrintf(PETSC_COMM_WORLD,"Initial - - - - - - - - -\n");
     72:     DSView(ds,viewer);
     73:   }

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

     89:   /* Print polynomial coefficients */
     90:   PetscPrintf(PETSC_COMM_WORLD,"Polynomial coefficients (alpha,beta,gamma) =\n");
     91:   DSPEPGetCoefficients(ds,&pbc);
     92:   for (j=0;j<3;j++) {
     93:     for (i=0;i<d+1;i++) {
     94:       PetscViewerASCIIPrintf(viewer,"  %.5f",(double)pbc[j+3*i]);
     95:     }
     96:     PetscViewerASCIIPrintf(viewer,"\n");
     97:   }
     98:   PetscFree(pbc);

    100:   /* Print eigenvalues */
    101:   PetscPrintf(PETSC_COMM_WORLD,"Computed eigenvalues =\n");
    102:   for (i=0;i<d*n;i++) {
    103: #if defined(PETSC_USE_COMPLEX)
    104:     re = PetscRealPart(wr[i]);
    105:     im = PetscImaginaryPart(wr[i]);
    106: #else
    107:     re = wr[i];
    108:     im = wi[i];
    109: #endif
    110:     if (PetscAbs(im)<1e-10) {
    111:       PetscViewerASCIIPrintf(viewer,"  %.5f\n",(double)re);
    112:     } else {
    113:       PetscViewerASCIIPrintf(viewer,"  %.5f%+.5fi\n",(double)re,(double)im);
    114:     }
    115:   }

    117:   /* Eigenvectors */
    118:   DSVectors(ds,DS_MAT_X,NULL,NULL);  /* all eigenvectors */
    119:   DSGetMat(ds,DS_MAT_X,&X);
    120:   MatCreateVecs(X,NULL,&x0);
    121:   MatGetColumnVector(X,x0,0);
    122:   VecNorm(x0,NORM_2,&nrm);
    123:   MatDestroy(&X);
    124:   VecDestroy(&x0);
    125:   PetscPrintf(PETSC_COMM_WORLD,"Norm of 1st vector = %.3f\n",(double)nrm);
    126:   if (verbose) {
    127:     PetscPrintf(PETSC_COMM_WORLD,"After vectors - - - - - - - - -\n");
    128:     DSView(ds,viewer);
    129:   }

    131:   PetscFree2(wr,wi);
    132:   DSDestroy(&ds);
    133:   SlepcFinalize();
    134:   return ierr;
    135: }

    137: /*TEST

    139:    test:
    140:       suffix: 1
    141:       requires: !single

    143: TEST*/