Actual source code: test1.c

slepc-3.11.2 2019-07-30
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  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 DSNHEP.\n\n";

 13: #include <slepcds.h>

 15: int main(int argc,char **argv)
 16: {
 18:   DS             ds;
 19:   SlepcSC        sc;
 20:   DSType         type;
 21:   DSStateType    state;
 22:   PetscScalar    *A,*X,*wr,*wi;
 23:   PetscReal      re,im,rnorm,aux;
 24:   PetscInt       i,j,n=10,ld,method;
 25:   PetscViewer    viewer;
 26:   PetscBool      verbose,extrarow;

 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 NHEP - dimension %D.\n",n);
 31:   PetscOptionsHasName(NULL,NULL,"-verbose",&verbose);
 32:   PetscOptionsHasName(NULL,NULL,"-extrarow",&extrarow);

 34:   /* Create DS object */
 35:   DSCreate(PETSC_COMM_WORLD,&ds);
 36:   DSSetType(ds,DSNHEP);
 37:   DSSetFromOptions(ds);
 38:   ld = n+2;  /* test leading dimension larger than n */
 39:   DSAllocate(ds,ld);
 40:   DSSetDimensions(ds,n,0,0,0);
 41:   DSSetExtraRow(ds,extrarow);

 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) {
 49:     PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_MATLAB);
 50:   }

 52:   /* Fill with Grcar matrix */
 53:   DSGetArray(ds,DS_MAT_A,&A);
 54:   for (i=1;i<n;i++) A[i+(i-1)*ld]=-1.0;
 55:   for (j=0;j<4;j++) {
 56:     for (i=0;i<n-j;i++) A[i+(i+j)*ld]=1.0;
 57:   }
 58:   if (extrarow) A[n+(n-1)*ld]=-1.0;
 59:   DSRestoreArray(ds,DS_MAT_A,&A);
 60:   DSSetState(ds,DS_STATE_INTERMEDIATE);
 61:   if (verbose) {
 62:     PetscPrintf(PETSC_COMM_WORLD,"Initial - - - - - - - - -\n");
 63:     DSView(ds,viewer);
 64:   }

 66:   /* Solve */
 67:   PetscMalloc2(n,&wr,n,&wi);
 68:   DSGetSlepcSC(ds,&sc);
 69:   sc->comparison    = SlepcCompareLargestMagnitude;
 70:   sc->comparisonctx = NULL;
 71:   sc->map           = NULL;
 72:   sc->mapobj        = NULL;
 73:   DSSolve(ds,wr,wi);
 74:   DSSort(ds,wr,wi,NULL,NULL,NULL);
 75:   if (extrarow) { DSUpdateExtraRow(ds); }

 77:   DSGetType(ds,&type);
 78:   DSGetMethod(ds,&method);
 79:   PetscPrintf(PETSC_COMM_WORLD,"DS of type %s, method used=%d\n",type,method);
 80:   DSGetState(ds,&state);
 81:   PetscPrintf(PETSC_COMM_WORLD,"State after solve: %s\n",DSStateTypes[state]);

 83:   if (verbose) {
 84:     PetscPrintf(PETSC_COMM_WORLD,"After solve - - - - - - - - -\n");
 85:     DSView(ds,viewer);
 86:   }

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

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

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

136: /*TEST

138:    test:
139:       suffix: 1
140:       requires: !complex !single

142: TEST*/