// @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 // Use of Epetra_FECrsMatrix // This code should be run with at least two processes #include "Didasko_ConfigDefs.h" #ifdef HAVE_DIDASKO_EPETRA #include "Epetra_ConfigDefs.h" #ifdef HAVE_MPI #include "mpi.h" #include "Epetra_MpiComm.h" #else #include "Epetra_SerialComm.h" #endif #include "Epetra_Map.h" #include "Epetra_Vector.h" #include "Epetra_FECrsMatrix.h" // =========== // // main driver // // ----------- // int main(int argc, char *argv[]) { #ifdef HAVE_MPI MPI_Init(&argc, &argv); Epetra_MpiComm Comm(MPI_COMM_WORLD); #else Epetra_SerialComm Comm; #endif // Create a linear map of size 10 (could be any number > 1) // // Note that a linear map is distributed approximately evenly over // all processors. // int NumGlobalElements = 10; Epetra_Map Map(NumGlobalElements,0,Comm); // create a diagonal FE crs matrix (one nonzero per row) Epetra_FECrsMatrix A(Copy,Map,1); // Next, set the matrix entries. // // Note 1: Matrix entries are only contributed from processor // 0, regardless of how many processors the program is running on. // Proc 0 fills the entire global matrix. Data that belongs in // matrix rows owned by procs 1 .. numprocs-1 gets sent to those // processors during the call to 'A.GlobalAssemble()' below. // // Note 2: We fill the matrix using 'InsertGlobalValues'. An // alternative approach that would be more efficient for large // matrices in most cases would be to first create and fill a // graph (Epetra_FECrsGraph), then construct the matrix with the // graph (after calling graph.FillComplete) and fill the matrix // using the method 'SumIntoGlobalValues'. // if( Comm.MyPID() == 0 ) { for( int i=0 ; i<NumGlobalElements ; ++i ) { int index = i; double value = 1.0*i; A.InsertGlobalValues(1,&index,&value); } } A.GlobalAssemble(); cout << A; #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"); #ifdef HAVE_MPI MPI_Finalize(); #endif return 0; } #endif