Date: 2013-09-02T10:09:49+00:00

Actual source code: test11.c

      1: /*
      2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
      3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
      4:    Copyright (c) 2002-2013, Universitat Politecnica de Valencia, Spain

      6:    This file is part of SLEPc.

      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 matrix exponential in DSNHEP.\n\n";

     24: #include <slepcds.h>
     25: #include <slepc-private/dsimpl.h>    /* for DSViewMat_Private() */

     29: int main(int argc,char **argv)
     30: {
     32:   DS             ds;
     33:   PetscScalar    *A;
     34:   PetscInt       i,j,n=10,ld;
     35:   PetscViewer    viewer;
     36:   PetscBool      verbose;

     38:   SlepcInitialize(&argc,&argv,(char*)0,help);
     39:   PetscOptionsGetInt(NULL,"-n",&n,NULL);
     40:   PetscPrintf(PETSC_COMM_WORLD,"Compute non-symmetric matrix exponential - dimension %D.\n",n);
     41:   PetscOptionsHasName(NULL,"-verbose",&verbose);

     43:   /* Create DS object */
     44:   DSCreate(PETSC_COMM_WORLD,&ds);
     45:   DSSetType(ds,DSNHEP);
     46:   DSSetFromOptions(ds);
     47:   ld = n+2;  /* test leading dimension larger than n */
     48:   DSAllocate(ds,ld);
     49:   DSSetDimensions(ds,n,0,0,0);

     51:   /* Set up viewer */
     52:   PetscViewerASCIIGetStdout(PETSC_COMM_WORLD,&viewer);
     53:   PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_INFO_DETAIL);
     54:   DSView(ds,viewer);
     55:   PetscViewerPopFormat(viewer);
     56:   if (verbose) {
     57:     PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_MATLAB);
     58:   }

     60:   /* Fill with a symmetric Toeplitz matrix */
     61:   DSGetArray(ds,DS_MAT_A,&A);
     62:   for (i=1;i<n;i++) A[i+(i-1)*ld]=-1.0;
     63:   for (j=0;j<4;j++) {
     64:     for (i=0;i<n-j;i++) A[i+(i+j)*ld]=1.0;
     65:   }
     66:   DSRestoreArray(ds,DS_MAT_A,&A);
     67:   DSSetState(ds,DS_STATE_INTERMEDIATE);
     68:   if (verbose) {
     69:     PetscPrintf(PETSC_COMM_WORLD,"Matrix A - - - - - - - -\n");
     70:     DSView(ds,viewer);
     71:   }

     73:   /* Compute matrix exponential */
     74:   DSComputeFunction(ds,SLEPC_FUNCTION_EXP);
     75:   if (verbose) {
     76:     PetscPrintf(PETSC_COMM_WORLD,"Computed f(A) - - - - - - -\n");
     77:     DSViewMat_Private(ds,viewer,DS_MAT_F);
     78:   }

     80:   DSDestroy(&ds);
     81:   SlepcFinalize();
     82:   return 0;
     83: }