// @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 // Basic definition of communicator. // This code should be run with one process #include "Didasko_ConfigDefs.h" #if defined(HAVE_DIDASKO_EPETRA) #include <iostream> #include "Epetra_ConfigDefs.h" #ifdef HAVE_MPI #include "mpi.h" #include "Epetra_MpiComm.h" #else #include "Epetra_SerialComm.h" #endif #include "Epetra_SerialDenseVector.h" #include "Epetra_SerialDenseMatrix.h" #include "Epetra_SerialDenseSolver.h" int main(int argc, char *argv[]) { #ifdef HAVE_MPI MPI_Init(&argc, &argv); Epetra_MpiComm Comm(MPI_COMM_WORLD); #else Epetra_SerialComm Comm; #endif // Total number of elements in vectors, can be any positive number int NumRows = 5; Epetra_SerialDenseVector x, b; x.Size( NumRows ); b.Size( NumRows ); // set the elements of the vector for( int i=0 ; i<NumRows ; ++i ) b[i] = 1.0, x[i]=0.0; Epetra_SerialDenseMatrix A, A2; A.Shape( NumRows, NumRows ); A2.Shape( NumRows, NumRows ); // A2 is a copy of A // Hilbert matrix (ill-conditioned) for( int i=0 ; i<NumRows ; ++i ) for( int j=0 ; j<NumRows ; ++j ) A(i,j) = 1.0/(i+j+2); cout<< A; // set up the solver Epetra_SerialDenseSolver Problem; Problem.SetMatrix( A ); Problem.SetVectors( x, b ); A2 = A; // we make a copy of A because Problem.Solve() will // overwrite A with its LU decomposition. Try with // cout << A after the following invocation b.Multiply('N','N',1.0, A2, x, 0.0); cout << "A * x = \n" << b; double rcond; Problem.ReciprocalConditionEstimate(rcond); cout << "The (estimated) condition number of A is " << 1/rcond << endl; Problem.SetMatrix( A2 ); Problem.Invert(); cout << "The inverse of A is\n"; cout << A2; #ifdef HAVE_MPI MPI_Finalize(); #endif } /* main */ #else #include <stdlib.h> #include <stdio.h> int main(int argc, char *argv[]) { puts("Please configure Didasko with:\n" "--enable-epetra"); return 0; } #endif