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// Didasko Tutorial Package
// Copyright (2005) Sandia Corporation
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// 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
#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