Subversion Repositories slepc-dev

/*

   - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

   SLEPc - Scalable Library for Eigenvalue Problem Computations

   Copyright (c) 2002-2011, Universitat Politecnica de Valencia, Spain

   This file is part of SLEPc.

   SLEPc is free software: you can redistribute it and/or modify it under  the

   terms of version 3 of the GNU Lesser General Public License as published by

   the Free Software Foundation.

   SLEPc  is  distributed in the hope that it will be useful, but WITHOUT  ANY

   WARRANTY;  without even the implied warranty of MERCHANTABILITY or  FITNESS

   FOR  A  PARTICULAR PURPOSE. See the GNU Lesser General Public  License  for

   more details.

   You  should have received a copy of the GNU Lesser General  Public  License

   along with SLEPc. If not, see <http://www.gnu.org/licenses/>.

   - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

*/

static char help[] = "Tests multiple calls to EPSSolve with different matrix.\n\n";

#include <slepceps.h>

#undef __FUNCT__

#define __FUNCT__ "main"

int main(int argc,char **argv)

{

  Mat            A1,A2;       /* problem matrices */

  EPS            eps;         /* eigenproblem solver context */

  PetscScalar    value[3];

  PetscReal      tol=1000*PETSC_MACHINE_EPSILON,v;

  Vec            d;

  PetscInt       n=30,i,Istart,Iend,col[3];

  PetscBool      FirstBlock=PETSC_FALSE,LastBlock=PETSC_FALSE;

  PetscRandom    myrand;

  PetscErrorCode ierr;

  SlepcInitialize(&argc,&argv,(char*)0,help);

  ierr = PetscOptionsGetInt(PETSC_NULL,"-n",&n,PETSC_NULL);CHKERRQ(ierr);

  ierr = PetscPrintf(PETSC_COMM_WORLD,"\nTridiagonal with random diagonal, n=%D\n\n",n);CHKERRQ(ierr);

  /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

           Create matrix tridiag([-1 0 -1])

     - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

  ierr = MatCreate(PETSC_COMM_WORLD,&A1);CHKERRQ(ierr);

  ierr = MatSetSizes(A1,PETSC_DECIDE,PETSC_DECIDE,n,n);CHKERRQ(ierr);

  ierr = MatSetFromOptions(A1);CHKERRQ(ierr);

  ierr = MatGetOwnershipRange(A1,&Istart,&Iend);CHKERRQ(ierr);

  if (Istart==0) FirstBlock=PETSC_TRUE;

  if (Iend==n) LastBlock=PETSC_TRUE;

  value[0]=-1.0; value[1]=0.0; value[2]=-1.0;

  for (i=(FirstBlock? Istart+1: Istart); i<(LastBlock? Iend-1: Iend); i++) {

    col[0]=i-1; col[1]=i; col[2]=i+1;

    ierr = MatSetValues(A1,1,&i,3,col,value,INSERT_VALUES);CHKERRQ(ierr);

  }

  if (LastBlock) {

    i=n-1; col[0]=n-2; col[1]=n-1;

    ierr = MatSetValues(A1,1,&i,2,col,value,INSERT_VALUES);CHKERRQ(ierr);

  }

  if (FirstBlock) {

    i=0; col[0]=0; col[1]=1; value[0]=0.0; value[1]=-1.0;

    ierr = MatSetValues(A1,1,&i,2,col,value,INSERT_VALUES);CHKERRQ(ierr);

  }

  ierr = MatAssemblyBegin(A1,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);

  ierr = MatAssemblyEnd(A1,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);

  /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

       Create two matrices by filling the diagonal with rand values

     - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

  ierr = MatDuplicate(A1,MAT_COPY_VALUES,&A2);CHKERRQ(ierr);

  ierr = MatGetVecs(A1,PETSC_NULL,&d);CHKERRQ(ierr);

  ierr = PetscRandomCreate(PETSC_COMM_WORLD,&myrand);CHKERRQ(ierr);

  ierr = PetscRandomSetFromOptions(myrand);CHKERRQ(ierr);

  ierr = PetscRandomSetInterval(myrand,0.0,1.0);CHKERRQ(ierr);

  for (i=0; i<n; i++) {

    ierr = PetscRandomGetValueReal(myrand,&v);CHKERRQ(ierr);

    ierr = VecSetValue(d,i,v,INSERT_VALUES);CHKERRQ(ierr);

  }

  ierr = VecAssemblyBegin(d);CHKERRQ(ierr);

  ierr = VecAssemblyEnd(d);CHKERRQ(ierr);

  ierr = MatDiagonalSet(A1,d,INSERT_VALUES);CHKERRQ(ierr);

  for (i=0; i<n; i++) {

    ierr = PetscRandomGetValueReal(myrand,&v);CHKERRQ(ierr);

    ierr = VecSetValue(d,i,v,INSERT_VALUES);CHKERRQ(ierr);

  }

  ierr = VecAssemblyBegin(d);CHKERRQ(ierr);

  ierr = VecAssemblyEnd(d);CHKERRQ(ierr);

  ierr = MatDiagonalSet(A2,d,INSERT_VALUES);CHKERRQ(ierr);

  ierr = VecDestroy(&d);CHKERRQ(ierr);

  ierr = PetscRandomDestroy(&myrand);CHKERRQ(ierr);

  /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

                        Create the eigensolver

     - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

  ierr = EPSCreate(PETSC_COMM_WORLD,&eps);CHKERRQ(ierr);

  ierr = EPSSetProblemType(eps,EPS_HEP);CHKERRQ(ierr);

  ierr = EPSSetTolerances(eps,tol,PETSC_DECIDE);CHKERRQ(ierr);

  ierr = EPSSetOperators(eps,A1,PETSC_NULL);CHKERRQ(ierr);

  ierr = EPSSetFromOptions(eps);CHKERRQ(ierr);

  /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

                        Solve first eigenproblem

     - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

  ierr = EPSSolve(eps);CHKERRQ(ierr);

  ierr = PetscPrintf(PETSC_COMM_WORLD," - - - First matrix - - -\n");CHKERRQ(ierr);

  ierr = EPSPrintSolution(eps,PETSC_NULL);CHKERRQ(ierr);

  /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

                        Solve second eigenproblem

     - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

  ierr = EPSSetOperators(eps,A2,PETSC_NULL);CHKERRQ(ierr);

  ierr = EPSSolve(eps);CHKERRQ(ierr);

  ierr = PetscPrintf(PETSC_COMM_WORLD," - - - Second matrix - - -\n");CHKERRQ(ierr);

  ierr = EPSPrintSolution(eps,PETSC_NULL);CHKERRQ(ierr);

  ierr = EPSDestroy(&eps);CHKERRQ(ierr);

  ierr = MatDestroy(&A1);CHKERRQ(ierr);

  ierr = MatDestroy(&A2);CHKERRQ(ierr);

  ierr = SlepcFinalize();CHKERRQ(ierr);

  return 0;

}