Epetra Package Browser (Single Doxygen Collection) Development
example/UG_Ex1/cxx_main.cpp
Go to the documentation of this file.
00001 /*
00002 //@HEADER
00003 // ************************************************************************
00004 // 
00005 //               Epetra: Linear Algebra Services Package 
00006 //                 Copyright 2001 Sandia Corporation
00007 // 
00008 // Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation,
00009 // the U.S. Government retains certain rights in this software.
00010 //
00011 // Redistribution and use in source and binary forms, with or without
00012 // modification, are permitted provided that the following conditions are
00013 // met:
00014 //
00015 // 1. Redistributions of source code must retain the above copyright
00016 // notice, this list of conditions and the following disclaimer.
00017 //
00018 // 2. Redistributions in binary form must reproduce the above copyright
00019 // notice, this list of conditions and the following disclaimer in the
00020 // documentation and/or other materials provided with the distribution.
00021 //
00022 // 3. Neither the name of the Corporation nor the names of the
00023 // contributors may be used to endorse or promote products derived from
00024 // this software without specific prior written permission.
00025 //
00026 // THIS SOFTWARE IS PROVIDED BY SANDIA CORPORATION "AS IS" AND ANY
00027 // EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
00028 // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
00029 // PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL SANDIA CORPORATION OR THE
00030 // CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
00031 // EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
00032 // PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
00033 // PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
00034 // LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
00035 // NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
00036 // SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
00037 //
00038 // Questions? Contact Michael A. Heroux (maherou@sandia.gov) 
00039 // 
00040 // ************************************************************************
00041 //@HEADER
00042 */
00043 
00044 #include <stdio.h>
00045 #include <stdlib.h>
00046 #include "Epetra_config.h"
00047 #ifdef HAVE_MPI
00048 #include "mpi.h"
00049 #include "Epetra_MpiComm.h"
00050 #else
00051 #include "Epetra_SerialComm.h"
00052 #endif
00053 #include "Epetra_Map.h"
00054 #include "Epetra_IntSerialDenseVector.h"
00055 #include "Epetra_SerialDenseVector.h"
00056 #include "Epetra_Vector.h"
00057 #include "Epetra_CrsMatrix.h"
00058 #include "Epetra_Version.h"
00059                                             
00060 // prototype
00061 double power_method(const Epetra_CrsMatrix& A);
00062 int main(int argc, char *argv[]) {
00063 #ifdef HAVE_MPI
00064   MPI_Init(&argc,&argv);
00065   Epetra_MpiComm Comm(MPI_COMM_WORLD);
00066 #else
00067   Epetra_SerialComm Comm;
00068 #endif
00069 
00070   if (Comm.MyPID()==0)
00071     cout << Epetra_Version() << endl << endl;
00072 
00073   cout << Comm << endl; // Print out process information
00074   // Get the number of global equations from the command line
00075   if (argc!=2) { 
00076     cout << "Usage: " << argv[0] << " number_of_equations" << endl;
00077     exit(1);
00078    }
00079   int NumGlobalElements = atoi(argv[1]);
00080   // Construct a Map that puts approximately the same number of 
00081   // equations on each processor.
00082   Epetra_Map Map(NumGlobalElements, 0, Comm);
00083   // Get update list and number of local equations from newly created Map.
00084   int NumMyElements = Map.NumMyElements();
00085   // Create an Epetra_CrsMatrix
00086   Epetra_CrsMatrix A(Copy, Map, 1);
00087  // Add  rows one-at-a-time
00088   Epetra_SerialDenseVector DiagVal(1); 
00089   DiagVal[0] = 2.0; // We set all diagonal values to 2
00090   Epetra_IntSerialDenseVector ColIndices(1);
00091   for (int i=0; i<NumMyElements; i++) {
00092     int RowIndex = Map.GID(i);
00093     ColIndices[0] = RowIndex;
00094     // Put in the diagonal entry
00095     A.InsertGlobalValues(RowIndex, DiagVal.Length(), 
00096        DiagVal.Values(), ColIndices.Values());  
00097   }
00098   if (Map.MyGID(0)) { // Change the first global diagonal value to 4.0
00099     DiagVal[0] = 4.0;
00100     int RowIndex = 0;
00101     ColIndices[0] = RowIndex;
00102   A.ReplaceGlobalValues(RowIndex, DiagVal.Length(), 
00103       DiagVal.Values(), ColIndices.Values());
00104   }
00105   // Finish up
00106  A.FillComplete();
00107   // Iterate
00108   double lambda = power_method(A);
00109   if (Comm.MyPID()==0) 
00110     cout << endl << "Estimate of Dominant Eigenvalue = " << lambda << endl;   
00111 #ifdef UG_EX1_MPI
00112   MPI_Finalize() ;
00113 #endif
00114 return 0;
00115 }
 All Classes Namespaces Files Functions Variables Typedefs Enumerations Enumerator Friends Defines