Actual source code: test19.c

slepc-3.11.2 2019-07-30
Report Typos and Errors
  1: /*
  2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
  4:    Copyright (c) 2002-2019, 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 DSSortWithPermutation() on a NHEP.\n\n";

 13: #include <slepcds.h>

 15: int main(int argc,char **argv)
 16: {
 18:   DS             ds;
 19:   SlepcSC        sc;
 20:   PetscScalar    *A,*wr,*wi;
 21:   PetscReal      re,im;
 22:   PetscInt       i,j,n=12,*perm;

 24:   SlepcInitialize(&argc,&argv,(char*)0,help);if (ierr) return ierr;
 25:   PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);
 26:   PetscPrintf(PETSC_COMM_WORLD,"Solve a Dense System of type NHEP - dimension %D.\n",n);

 28:   /* Create DS object */
 29:   DSCreate(PETSC_COMM_WORLD,&ds);
 30:   DSSetType(ds,DSNHEP);
 31:   DSSetFromOptions(ds);
 32:   DSAllocate(ds,n);
 33:   DSSetDimensions(ds,n,0,0,0);

 35:   /* Fill with Grcar matrix */
 36:   DSGetArray(ds,DS_MAT_A,&A);
 37:   for (i=1;i<n;i++) A[i+(i-1)*n]=-1.0;
 38:   for (j=0;j<4;j++) {
 39:     for (i=0;i<n-j;i++) A[i+(i+j)*n]=1.0;
 40:   }
 41:   DSRestoreArray(ds,DS_MAT_A,&A);
 42:   DSSetState(ds,DS_STATE_INTERMEDIATE);

 44:   /* Solve */
 45:   PetscMalloc3(n,&wr,n,&wi,n,&perm);
 46:   DSGetSlepcSC(ds,&sc);
 47:   sc->comparison    = SlepcCompareLargestMagnitude;
 48:   sc->comparisonctx = NULL;
 49:   sc->map           = NULL;
 50:   sc->mapobj        = NULL;
 51:   DSSolve(ds,wr,wi);
 52:   DSSort(ds,wr,wi,NULL,NULL,NULL);

 54:   /* Print eigenvalues */
 55:   PetscPrintf(PETSC_COMM_WORLD,"Computed eigenvalues =\n");
 56:   for (i=0;i<n;i++) {
 57: #if defined(PETSC_USE_COMPLEX)
 58:     re = PetscRealPart(wr[i]);
 59:     im = PetscImaginaryPart(wr[i]);
 60: #else
 61:     re = wr[i];
 62:     im = wi[i];
 63: #endif
 64:     if (PetscAbs(im)<1e-10) {
 65:       PetscPrintf(PETSC_COMM_WORLD,"  %.5f\n",(double)re);
 66:     } else {
 67:       PetscPrintf(PETSC_COMM_WORLD,"  %.5f%+.5fi\n",(double)re,(double)im);
 68:     }
 69:   }

 71:   /* Reorder eigenvalues */
 72:   for (i=0;i<n/2;i++) perm[i] = n/2+i;
 73:   for (i=0;i<n/2;i++) perm[i+n/2] = i;
 74:   DSSortWithPermutation(ds,perm,wr,wi);
 75:   PetscPrintf(PETSC_COMM_WORLD,"Reordered eigenvalues =\n");
 76:   for (i=0;i<n;i++) {
 77: #if defined(PETSC_USE_COMPLEX)
 78:     re = PetscRealPart(wr[i]);
 79:     im = PetscImaginaryPart(wr[i]);
 80: #else
 81:     re = wr[i];
 82:     im = wi[i];
 83: #endif
 84:     if (PetscAbs(im)<1e-10) {
 85:       PetscPrintf(PETSC_COMM_WORLD,"  %.5f\n",(double)re);
 86:     } else {
 87:       PetscPrintf(PETSC_COMM_WORLD,"  %.5f%+.5fi\n",(double)re,(double)im);
 88:     }
 89:   }

 91:   PetscFree3(wr,wi,perm);
 92:   DSDestroy(&ds);
 93:   SlepcFinalize();
 94:   return ierr;
 95: }

 97: /*TEST

 99:    test:
100:       suffix: 1
101:       requires: !complex

103: TEST*/