一个简单的例子

cxx_main.cpp  源码见后面，是从trilinos中找的一个例子。

现在的任务是写一个 Makefile 文件，我们可以编译文件。

原来的trilinos 版本的Makefile文件中最大的困难就是 排列链接库文件的先后顺序，现在这个情况改善了。

只要下面的Makefile 即可

tlu@tlu-laptop:~/a$ cat Makefile
################################################################################
## Example Makefile that builds “cxx_main.exe” example outside of Trilinos
## 这是一个仅仅用到Epetra 的小例子
################################################################################
## Set the Trilinos install directory
Trilinos_INSTALL_DIR = /home/tlu/trilinos10
## Include any direct Trilinos library dependencies - in this case only nox
include $(Trilinos_INSTALL_DIR)/include/Makefile.export.Trilinos
COMPILE_FLAGS = $(Trilinos_CXX_FLAGS) $(Trilinos_INCLUDE_DIRS)
# TPL => "Third Party Library"
LINK_FLAGS = $(Trilinos_LIBRARY_DIRS) $(Trilinos_LIBRARIES) \
$(Trilinos_TPL_LIBRARY_DIRS) $(Trilinos_TPL_LIBRARIES) $(Trilinos_EXTRA_LD_FLAGS)
## ## Build your application code ##
cxx_main.exe: cxx_main.o
    $(Trilinos_CXX_COMPILER) $(Trilinos_CXX_FLAGS) -o cxx_main.exe cxx_main.o $(LINK_FLAGS)
cxx_main.o: cxx_main.cpp
    $(Trilinos_CXX_COMPILER) $(COMPILE_FLAGS) -c cxx_main.cpp
clean:
    \rm -f *.o *.exe *~
tlu@tlu-laptop:~/a$

--------------------------------

tlu@tlu-laptop:~/a$ cat cxx_main.cpp
//@HEADER
// ************************************************************************
//
//               Epetra: Linear Algebra Services Package
//                 Copyright 2001 Sandia Corporation
//
// Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation,
// the U.S. Government retains certain rights in this software.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// 1. Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
//
// 3. Neither the name of the Corporation nor the names of the
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY SANDIA CORPORATION "AS IS" AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
// PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL SANDIA CORPORATION OR THE
// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// Questions? Contact Michael A. Heroux (maherou@sandia.gov)
//
// ************************************************************************
//@HEADER


#include "Epetra_SerialComm.h"
#include "Epetra_Map.h"
#include "Epetra_Vector.h"
#include "Epetra_Version.h"

int main(int argc, char *argv[])
{

  cout << Epetra_Version() << endl << endl;

  Epetra_SerialComm Comm;

  int NumElements = 1000;

  // Construct a Map with NumElements and index base of 0
  Epetra_Map Map(NumElements, 0, Comm);

  // Create x and b vectors
  Epetra_Vector x(Map);
  Epetra_Vector b(Map);

  b.Random();
  x.Update(2.0, b, 0.0); // x = 2*b

  double bnorm, xnorm;
  x.Norm2(&xnorm);
  b.Norm2(&bnorm);

  cout << "2 norm of x = " << xnorm << endl
       << "2 norm of b = " << bnorm << endl;

  return 0;
}

tlu@tlu-laptop:~/a$