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example/UG_Ex1/cxx_main.cpp
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1/*
2//@HEADER
3// ************************************************************************
4//
5// Epetra: Linear Algebra Services Package
6// Copyright 2011 Sandia Corporation
7//
8// Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation,
9// the U.S. Government retains certain rights in this software.
10//
11// Redistribution and use in source and binary forms, with or without
12// modification, are permitted provided that the following conditions are
13// met:
14//
15// 1. Redistributions of source code must retain the above copyright
16// notice, this list of conditions and the following disclaimer.
17//
18// 2. Redistributions in binary form must reproduce the above copyright
19// notice, this list of conditions and the following disclaimer in the
20// documentation and/or other materials provided with the distribution.
21//
22// 3. Neither the name of the Corporation nor the names of the
23// contributors may be used to endorse or promote products derived from
24// this software without specific prior written permission.
25//
26// THIS SOFTWARE IS PROVIDED BY SANDIA CORPORATION "AS IS" AND ANY
27// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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38// Questions? Contact Michael A. Heroux (maherou@sandia.gov)
39//
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42*/
43
44#include <stdio.h>
45#include <stdlib.h>
46#include "Epetra_config.h"
47#ifdef HAVE_MPI
48#include "mpi.h"
49#include "Epetra_MpiComm.h"
50#else
51#include "Epetra_SerialComm.h"
52#endif
53#include "Epetra_Map.h"
56#include "Epetra_Vector.h"
57#include "Epetra_CrsMatrix.h"
58#include "Epetra_Version.h"
59
60// prototype
61double power_method(const Epetra_CrsMatrix& A);
62int main(int argc, char *argv[]) {
63#ifdef HAVE_MPI
64 MPI_Init(&argc,&argv);
65 Epetra_MpiComm Comm(MPI_COMM_WORLD);
66#else
68#endif
69
70 if (Comm.MyPID()==0)
71 std::cout << Epetra_Version() << std::endl << std::endl;
72
73 std::cout << Comm << std::endl; // Print out process information
74 // Get the number of global equations from the command line
75 if (argc!=2) {
76 std::cout << "Usage: " << argv[0] << " number_of_equations" << std::endl;
77 exit(1);
78 }
79 int NumGlobalElements = atoi(argv[1]);
80 // Construct a Map that puts approximately the same number of
81 // equations on each processor.
82 Epetra_Map Map(NumGlobalElements, 0, Comm);
83 // Get update list and number of local equations from newly created Map.
84 int NumMyElements = Map.NumMyElements();
85 // Create an Epetra_CrsMatrix
86 Epetra_CrsMatrix A(Copy, Map, 1);
87 // Add rows one-at-a-time
88 Epetra_SerialDenseVector DiagVal(1);
89 DiagVal[0] = 2.0; // We set all diagonal values to 2
90 Epetra_IntSerialDenseVector ColIndices(1);
91 for (int i=0; i<NumMyElements; i++) {
92 int RowIndex = Map.GID(i);
93 ColIndices[0] = RowIndex;
94 // Put in the diagonal entry
95 A.InsertGlobalValues(RowIndex, DiagVal.Length(),
96 DiagVal.Values(), ColIndices.Values());
97 }
98 if (Map.MyGID(0)) { // Change the first global diagonal value to 4.0
99 DiagVal[0] = 4.0;
100 int RowIndex = 0;
101 ColIndices[0] = RowIndex;
102 A.ReplaceGlobalValues(RowIndex, DiagVal.Length(),
103 DiagVal.Values(), ColIndices.Values());
104 }
105 // Finish up
106 A.FillComplete();
107 // Iterate
108 double lambda = power_method(A);
109 if (Comm.MyPID()==0)
110 std::cout << std::endl << "Estimate of Dominant Eigenvalue = " << lambda << std::endl;
111#ifdef UG_EX1_MPI
112 MPI_Finalize() ;
113#endif
114return 0;
115}
std::string Epetra_Version()
int GID(int LID) const
Returns global ID of local ID, return IndexBase-1 if not found on this processor.
int NumMyElements() const
Number of elements on the calling processor.
bool MyGID(int GID_in) const
Returns true if the GID passed in belongs to the calling processor in this map, otherwise returns fal...
Epetra_CrsMatrix: A class for constructing and using real-valued double-precision sparse compressed r...
int FillComplete(bool OptimizeDataStorage=true)
Signal that data entry is complete. Perform transformations to local index space.
virtual int ReplaceGlobalValues(int GlobalRow, int NumEntries, const double *Values, const int *Indices)
Replace specified existing values with this list of entries for a given global row of the matrix.
virtual int InsertGlobalValues(int GlobalRow, int NumEntries, const double *Values, const int *Indices)
Insert a list of elements in a given global row of the matrix.
Epetra_IntSerialDenseVector: A class for constructing and using dense vectors.
int * Values()
Returns pointer to the values in vector.
Epetra_Map: A class for partitioning vectors and matrices.
Definition Epetra_Map.h:119
Epetra_MpiComm: The Epetra MPI Communication Class.
int MyPID() const
Return my process ID.
Epetra_SerialComm: The Epetra Serial Communication Class.
Epetra_SerialDenseVector: A class for constructing and using dense vectors.
double * Values() const
Returns pointer to the values in vector.
int Length() const
Returns length of vector.
int main(int argc, char *argv[])
double power_method(const Epetra_CrsMatrix &A)