xref: /petsc/src/sys/tests/ex45.cxx (revision 6a98f8dc3f2c9149905a87dc2e9d0fedaf64e09a)
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 
12 
13 #include <petscsys.h>
14 #include <Teuchos_DefaultMpiComm.hpp> // wrapper for MPI_Comm
15 #include <Tpetra_Version.hpp> // Tpetra version string
16 
17 // Do something with the given communicator.  In this case, we just
18 // print Tpetra's version to stdout on Process 0 in the given
19 // communicator.
20 void
21 exampleRoutine (const Teuchos::RCP<const Teuchos::Comm<int> >& comm)
22 {
23   if (comm->getRank () == 0) {
24     // On (MPI) Process 0, print out the Tpetra software version.
25     std::cout << Tpetra::version () << std::endl << std::endl;
26   }
27 }
28 
29 int main(int argc,char **argv)
30 {
31   PetscErrorCode ierr;
32   // These "using" declarations make the code more concise, in that
33   // you don't have to write the namespace along with the class or
34   // object name.  This is especially helpful with commonly used
35   // things like std::endl or Teuchos::RCP.
36   using std::cout;
37   using std::endl;
38   using Teuchos::Comm;
39   using Teuchos::MpiComm;
40   using Teuchos::RCP;
41   using Teuchos::rcp;
42 
43   /*
44     Every PETSc routine should begin with the PetscInitialize() routine.
45     argc, argv - These command line arguments are taken to extract the options
46                  supplied to PETSc and options supplied to MPI.
47     help       - When PETSc executable is invoked with the option -help,
48                  it prints the various options that can be applied at
49                  runtime.  The user can use the "help" variable place
50                  additional help messages in this printout.
51   */
52   ierr = PetscInitialize(&argc,&argv,(char*)0,help);if (ierr) return ierr;
53   RCP<const Comm<int> > comm (new MpiComm<int> (PETSC_COMM_WORLD));
54   // Get my process' rank, and the total number of processes.
55   // Equivalent to MPI_Comm_rank resp. MPI_Comm_size.
56   const int myRank = comm->getRank ();
57   const int size = comm->getSize ();
58   if (myRank == 0) {
59     cout << "Total number of processes: " << size << endl;
60   }
61   // Do something with the new communicator.
62   exampleRoutine (comm);
63   // This tells the Trilinos test framework that the test passed.
64   if (myRank == 0) {
65     cout << "End Result: TEST PASSED" << endl;
66   }
67 
68   ierr = PetscFinalize();
69   return ierr;
70 }
71 
72 
73 /*TEST
74 
75    build:
76      requires: trilinos
77 
78    test:
79       nsize: 3
80       filter: grep -v "Tpetra in Trilinos"
81 
82 TEST*/
83