// @HEADER // *********************************************************************** // // Didasko Tutorial Package // Copyright (2005) Sandia Corporation // // Under terms of Contract DE-AC04-94AL85000, there is a non-exclusive // license for use of this work by or on behalf of the U.S. Government. // // This library is free software; you can redistribute it and/or modify // it under the terms of the GNU Lesser General Public License as // published by the Free Software Foundation; either version 2.1 of the // License, or (at your option) any later version. // // This library 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 this library; if not, write to the Free Software // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 // USA // // Questions about Didasko? Contact Marzio Sala (marzio.sala _AT_ gmail.com) // // *********************************************************************** // @HEADER // Solve a linear system with AztecOO. // The linear system is created using MatrixGallery #include "Didasko_ConfigDefs.h" #if defined(HAVE_DIDASKO_EPETRA) && defined(HAVE_DIDASKO_TRIUTILS) #include "Epetra_ConfigDefs.h" #ifdef HAVE_MPI #include "mpi.h" #include "Epetra_MpiComm.h" #else #include "Epetra_SerialComm.h" #endif #include "AztecOO.h" #include "Epetra_CrsMatrix.h" #include "Trilinos_Util_CrsMatrixGallery.h" using namespace Trilinos_Util; int main(int argc, char *argv[]) { #ifdef HAVE_MPI MPI_Init(&argc,&argv); Epetra_MpiComm Comm(MPI_COMM_WORLD); #else Epetra_SerialComm Comm; #endif // initialize an Gallery object CrsMatrixGallery Gallery("laplace_2d", Comm); Gallery.Set("problem_size",900); // Get pointers to the linear problem (containing matrix, LHS and RHS). Epetra_LinearProblem * Problem= Gallery.GetLinearProblem(); // initialize the AztecOO solve object, based on current linear problem AztecOO solver(*Problem); // here set some AztecOO options: // - symmetric problem; // - domain decomposition preconditioner // - ICC factorization on each subdomain solver.SetAztecOption(AZ_solver, AZ_cg_condnum); solver.SetAztecOption(AZ_precond, AZ_dom_decomp); solver.SetAztecOption(AZ_overlap,0); solver.SetAztecOption(AZ_subdomain_solve, AZ_icc); // solve the linear system solver.Iterate(1550, 1e-12); // AztecOO defined a certain number of output parameters, and store them // in a double vector called status. double status[AZ_STATUS_SIZE]; solver.GetAllAztecStatus(status); // verify that linear system has been solved as required double residual, diff; Gallery.ComputeResidual(&residual); Gallery.ComputeDiffBetweenStartingAndExactSolutions(&diff); if( Comm.MyPID()==0 ) { cout << "||b-Ax||_2 = " << residual << endl; cout << "||x_exact - x||_2 = " << diff << endl; } #ifdef HAVE_MPI MPI_Finalize(); #endif return(EXIT_SUCCESS); } #else #include <stdlib.h> #include <stdio.h> #ifdef HAVE_MPI #include "mpi.h" #endif int main(int argc, char *argv[]) { #ifdef HAVE_MPI MPI_Init(&argc,&argv); #endif puts("Please configure Didasko with:\n" "--enable-epetra\n" "--enable-triutils\n" "--enable-aztecoo\n"); #ifdef HAVE_MPI MPI_Finalize(); #endif return 0; } #endif