Actual source code: test3.c

slepc-3.7.0 2016-05-16
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  1: /*
  2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
  4:    Copyright (c) 2002-2016, 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[] = "Tests multiple calls to EPSSolve with different matrix.\n\n";

 24: #include <slepceps.h>

 28: int main(int argc,char **argv)
 29: {
 30:   Mat            A1,A2;       /* problem matrices */
 31:   EPS            eps;         /* eigenproblem solver context */
 32:   PetscReal      tol=1000*PETSC_MACHINE_EPSILON,v;
 33:   Vec            d;
 34:   PetscInt       n=30,i,Istart,Iend;
 35:   PetscRandom    myrand;

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

 40:   PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);
 41:   PetscPrintf(PETSC_COMM_WORLD,"\nTridiagonal with random diagonal, n=%D\n\n",n);

 43:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 44:            Create matrix tridiag([-1 0 -1])
 45:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
 46:   MatCreate(PETSC_COMM_WORLD,&A1);
 47:   MatSetSizes(A1,PETSC_DECIDE,PETSC_DECIDE,n,n);
 48:   MatSetFromOptions(A1);
 49:   MatSetUp(A1);

 51:   MatGetOwnershipRange(A1,&Istart,&Iend);
 52:   for (i=Istart;i<Iend;i++) {
 53:     if (i>0) { MatSetValue(A1,i,i-1,-1.0,INSERT_VALUES); }
 54:     if (i<n-1) { MatSetValue(A1,i,i+1,-1.0,INSERT_VALUES); }
 55:   }
 56:   MatAssemblyBegin(A1,MAT_FINAL_ASSEMBLY);
 57:   MatAssemblyEnd(A1,MAT_FINAL_ASSEMBLY);

 59:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 60:        Create two matrices by filling the diagonal with rand values
 61:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
 62:   MatDuplicate(A1,MAT_COPY_VALUES,&A2);
 63:   MatCreateVecs(A1,NULL,&d);
 64:   PetscRandomCreate(PETSC_COMM_WORLD,&myrand);
 65:   PetscRandomSetFromOptions(myrand);
 66:   PetscRandomSetInterval(myrand,0.0,1.0);
 67:   for (i=Istart;i<Iend;i++) {
 68:     PetscRandomGetValueReal(myrand,&v);
 69:     VecSetValue(d,i,v,INSERT_VALUES);
 70:   }
 71:   VecAssemblyBegin(d);
 72:   VecAssemblyEnd(d);
 73:   MatDiagonalSet(A1,d,INSERT_VALUES);
 74:   for (i=Istart;i<Iend;i++) {
 75:     PetscRandomGetValueReal(myrand,&v);
 76:     VecSetValue(d,i,v,INSERT_VALUES);
 77:   }
 78:   VecAssemblyBegin(d);
 79:   VecAssemblyEnd(d);
 80:   MatDiagonalSet(A2,d,INSERT_VALUES);
 81:   VecDestroy(&d);
 82:   PetscRandomDestroy(&myrand);

 84:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 85:                         Create the eigensolver
 86:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
 87:   EPSCreate(PETSC_COMM_WORLD,&eps);
 88:   EPSSetProblemType(eps,EPS_HEP);
 89:   EPSSetTolerances(eps,tol,PETSC_DEFAULT);
 90:   EPSSetOperators(eps,A1,NULL);
 91:   EPSSetFromOptions(eps);

 93:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 94:                         Solve first eigenproblem
 95:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
 96:   EPSSolve(eps);
 97:   PetscPrintf(PETSC_COMM_WORLD," - - - First matrix - - -\n");
 98:   EPSErrorView(eps,EPS_ERROR_RELATIVE,NULL);

100:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
101:                         Solve second eigenproblem
102:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
103:   EPSSetOperators(eps,A2,NULL);
104:   EPSSolve(eps);
105:   PetscPrintf(PETSC_COMM_WORLD," - - - Second matrix - - -\n");
106:   EPSErrorView(eps,EPS_ERROR_RELATIVE,NULL);

108:   EPSDestroy(&eps);
109:   MatDestroy(&A1);
110:   MatDestroy(&A2);
111:   SlepcFinalize();
112:   return ierr;
113: }