// @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? Contact Michael A. Heroux (maherou@sandia.gov) // // *********************************************************************** // @HEADER // Use of ExtractView of Epetra_Vector #include "Didasko_ConfigDefs.h" #if defined(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" 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 the vector int NumElements = 10; // Construct a Map with NumElements and index base of 0 Epetra_Map Map(NumElements, 0, Comm); // Create x as an Epetra_vector Epetra_Vector x(Map); // get the local size of the vector int MyLength = x.MyLength(); /* First way to define the vector: */ /* use the [] operator on the object */ for( int i=0 ; i<MyLength ; ++i ) x[i] = 1.0*i; // need a double pointer because this works with multi-vectors double * pointer; x.ExtractView( &pointer ); for( int i=0 ; i<MyLength ; ++i ) cout << "on proc " << Comm.MyPID() << ", x[" << i << "] = " << pointer[i] << endl; // now modify the values for( int i=0 ; i<MyLength ; ++i ) pointer[i] *= 10; // this affects the object x cout << x; #ifdef HAVE_MPI MPI_Finalize(); #endif return(EXIT_SUCCESS); } /* 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