1MPI_Graph_get(3) LAM/MPI MPI_Graph_get(3)
2
6 MPI_Graph_get - Retrieves graph topology information associated with a
7 communicator
8
10 #include <mpi.h>
11 int MPI_Graph_get(MPI_Comm comm, int maxnodes, int maxedges,
12 int *nodes, int *edges)
13
15 comm - communicator with graph structure (handle)
16 maxnodes
17 - length of vector index in the calling program (integer)
18 maxedges
19 - length of vector edges in the calling program (integer)
20
23 nodes - array of integers containing the graph structure (for details
24 see the definition of MPI_GRAPH_CREATE )
25 edges - array of integers containing the graph structure
26
29 All MPI routines in Fortran (except for MPI_WTIME and MPI_WTICK ) have
30 an additional argument ierr at the end of the argument list. ierr is
31 an integer and has the same meaning as the return value of the routine
32 in C. In Fortran, MPI routines are subroutines, and are invoked with
33 the call statement.
34 All MPI objects (e.g., MPI_Datatype , MPI_Comm ) are of type INTEGER in
36 Fortran.
37
40 If an error occurs in an MPI function, the current MPI error handler is
41 called to handle it. By default, this error handler aborts the MPI
42 job. The error handler may be changed with MPI_Errhandler_set ; the
43 predefined error handler MPI_ERRORS_RETURN may be used to cause error
44 values to be returned (in C and Fortran; this error handler is less
45 useful in with the C++ MPI bindings. The predefined error handler
46 MPI::ERRORS_THROW_EXCEPTIONS should be used in C++ if the error value
47 needs to be recovered). Note that MPI does not guarantee that an MPI
48 program can continue past an error.
49 All MPI routines (except MPI_Wtime and MPI_Wtick ) return an error
51 value; C routines as the value of the function and Fortran routines in
52 the last argument. The C++ bindings for MPI do not return error val‐
53 ues; instead, error values are communicated by throwing exceptions of
54 type MPI::Exception (but not by default). Exceptions are only thrown
55 if the error value is not MPI::SUCCESS .
56 Note that if the MPI::ERRORS_RETURN handler is set in C++, while MPI
59 functions will return upon an error, there will be no way to recover
60 what the actual error value was.
61 MPI_SUCCESS
62 - No error; MPI routine completed successfully.
63 MPI_ERR_TOPOLOGY
64 - Invalid topology. Either there is no topology associated with
65 this communicator, or it is not the correct type (e.g., MPI_CART
66 when expecting MPI_GRAPH ).
67 MPI_ERR_COMM
68 - Invalid communicator. A common error is to use a null commu‐
69 nicator in a call (not even allowed in MPI_Comm_rank ).
70 MPI_ERR_ARG
71 - Invalid argument. Some argument is invalid and is not identi‐
72 fied by a specific error class. This is typically a NULL
73 pointer or other such error.
74
77 For more information, please see the official MPI Forum web site, which
78 contains the text of both the MPI-1 and MPI-2 standards. These docu‐
79 ments contain detailed information about each MPI function (most of
80 which is not duplicated in these man pages).
81 http://www.mpi-forum.org/
83
87 The LAM Team would like the thank the MPICH Team for the handy program
88 to generate man pages ("doctext" from ftp://ftp.mcs.anl.gov/pub/sow‐
89 ing/sowing.tar.gz ), the initial formatting, and some initial text for
90 most of the MPI-1 man pages.
91
93 graphget.c
94LAM/MPI 7.1.2 2/23/2006 MPI_Graph_get(3)