xref: /petsc/src/sys/tests/ex45.cxx (revision 030f984af8d8bb4c203755d35bded3c05b3d83ce)
1 
2 static char help[] = "Demonstrates call PETSc first and then Trilinos in the same program.\n\n";
3 
4 /*T
5    Concepts: introduction to PETSc^Trilinos
6    Processors: n
7 
8    Example obtained from: http://trilinos.org/docs/dev/packages/tpetra/doc/html/Tpetra_Lesson01.html
9 T*/
10 
11 #include <petscsys.h>
12 #include <Teuchos_DefaultMpiComm.hpp> // wrapper for MPI_Comm
13 #include <Tpetra_Version.hpp> // Tpetra version string
14 
15 // Do something with the given communicator.  In this case, we just
16 // print Tpetra's version to stdout on Process 0 in the given
17 // communicator.
18 void
19 exampleRoutine (const Teuchos::RCP<const Teuchos::Comm<int> >& comm)
20 {
21   if (comm->getRank () == 0) {
22     // On (MPI) Process 0, print out the Tpetra software version.
23     std::cout << Tpetra::version () << std::endl << std::endl;
24   }
25 }
26 
27 int main(int argc,char **argv)
28 {
29   PetscErrorCode ierr;
30   // These "using" declarations make the code more concise, in that
31   // you don't have to write the namespace along with the class or
32   // object name.  This is especially helpful with commonly used
33   // things like std::endl or Teuchos::RCP.
34   using std::cout;
35   using std::endl;
36   using Teuchos::Comm;
37   using Teuchos::MpiComm;
38   using Teuchos::RCP;
39   using Teuchos::rcp;
40 
41   /*
42     Every PETSc routine should begin with the PetscInitialize() routine.
43     argc, argv - These command line arguments are taken to extract the options
44                  supplied to PETSc and options supplied to MPI.
45     help       - When PETSc executable is invoked with the option -help,
46                  it prints the various options that can be applied at
47                  runtime.  The user can use the "help" variable place
48                  additional help messages in this printout.
49   */
50   ierr = PetscInitialize(&argc,&argv,(char*)0,help);if (ierr) return ierr;
51   RCP<const Comm<int> > comm (new MpiComm<int> (PETSC_COMM_WORLD));
52   // Get my process' rank, and the total number of processes.
53   // Equivalent to MPI_Comm_rank resp. MPI_Comm_size.
54   const int myRank = comm->getRank ();
55   const int size = comm->getSize ();
56   if (myRank == 0) {
57     cout << "Total number of processes: " << size << endl;
58   }
59   // Do something with the new communicator.
60   exampleRoutine (comm);
61   // This tells the Trilinos test framework that the test passed.
62   if (myRank == 0) {
63     cout << "End Result: TEST PASSED" << endl;
64   }
65 
66   ierr = PetscFinalize();
67   return ierr;
68 }
69 
70 /*TEST
71 
72    build:
73      requires: trilinos
74 
75    test:
76       nsize: 3
77       filter: grep -v "Tpetra in Trilinos"
78 
79 TEST*/
80