Actual source code: test11.c

slepc-3.5.2 2014-10-10
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  1: /*
  2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
  4:    Copyright (c) 2002-2014, 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>

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

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

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

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

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

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

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