Actual source code: test3.c

  1: /*
  2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
  4:    Copyright (c) 2002-2012, Universitat Politecnica de Valencia, Spain

  6:    This file is part of SLEPc.
  7:       
  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 DSHEP with compact storage.\n\n";

 24:  #include slepcds.h

 28: int main( int argc, char **argv )
 29: {
 31:   DS             ds;
 32:   PetscReal      *T;
 33:   PetscScalar    *eig;
 34:   PetscInt       i,n=10,l=2,k=5,ld;
 35:   PetscViewer    viewer;
 36:   PetscBool      verbose,extrarow;

 38:   SlepcInitialize(&argc,&argv,(char*)0,help);
 39:   PetscOptionsGetInt(PETSC_NULL,"-n",&n,PETSC_NULL);
 40:   PetscPrintf(PETSC_COMM_WORLD,"Solve a Dense System of type HEP with compact storage - dimension %D.\n",n);
 41:   PetscOptionsGetInt(PETSC_NULL,"-l",&l,PETSC_NULL);
 42:   PetscOptionsGetInt(PETSC_NULL,"-k",&k,PETSC_NULL);
 43:   if (l>n || k>n || l>k) SETERRQ(PETSC_COMM_WORLD,1,"Wrong value of dimensions");
 44:   PetscOptionsHasName(PETSC_NULL,"-verbose",&verbose);
 45:   PetscOptionsHasName(PETSC_NULL,"-extrarow",&extrarow);

 47:   /* Create DS object */
 48:   DSCreate(PETSC_COMM_WORLD,&ds);
 49:   DSSetType(ds,DSHEP);
 50:   DSSetFromOptions(ds);
 51:   ld = n+2;  /* test leading dimension larger than n */
 52:   DSAllocate(ds,ld);
 53:   DSSetDimensions(ds,n,PETSC_IGNORE,l,k);
 54:   DSSetCompact(ds,PETSC_TRUE);
 55:   DSSetExtraRow(ds,extrarow);

 57:   /* Set up viewer */
 58:   PetscViewerASCIIGetStdout(PETSC_COMM_WORLD,&viewer);
 59:   PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_INFO_DETAIL);
 60:   DSView(ds,viewer);
 61:   PetscViewerPopFormat(viewer);
 62:   if (verbose) {
 63:     PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_MATLAB);
 64:   }

 66:   /* Fill arrow-tridiagonal matrix */
 67:   DSGetArrayReal(ds,DS_MAT_T,&T);
 68:   for (i=0;i<n;i++) T[i] = (PetscReal)(i+1);
 69:   for (i=l;i<n-1;i++) T[i+ld] = 1.0;
 70:   if (extrarow) T[n-1+ld] = 1.0;
 71:   DSRestoreArrayReal(ds,DS_MAT_T,&T);
 72:   if (l==0 && k==0) {
 73:     DSSetState(ds,DS_STATE_INTERMEDIATE);
 74:   } else {
 75:     DSSetState(ds,DS_STATE_RAW);
 76:   }
 77:   if (verbose) {
 78:     PetscPrintf(PETSC_COMM_WORLD,"Initial - - - - - - - - -\n");
 79:     DSView(ds,viewer);
 80:   }

 82:   /* Solve */
 83:   PetscMalloc(n*sizeof(PetscScalar),&eig);
 84:   DSSetEigenvalueComparison(ds,SlepcCompareLargestMagnitude,PETSC_NULL);
 85:   DSSolve(ds,eig,PETSC_NULL);
 86:   DSSort(ds,eig,PETSC_NULL,PETSC_NULL,PETSC_NULL,PETSC_NULL);
 87:   if (extrarow) { DSUpdateExtraRow(ds); }
 88:   if (verbose) {
 89:     PetscPrintf(PETSC_COMM_WORLD,"After solve - - - - - - - - -\n");
 90:     DSView(ds,viewer);
 91:   }

 93:   /* Print eigenvalues */
 94:   PetscPrintf(PETSC_COMM_WORLD,"Computed eigenvalues =\n",n);
 95:   for (i=0;i<n;i++) {
 96:     PetscViewerASCIIPrintf(viewer,"  %.5F\n",PetscRealPart(eig[i]));
 97:   }

 99:   PetscFree(eig);
100:   DSDestroy(&ds);
101:   SlepcFinalize();
102:   return 0;
103: }