1MPI_Graphdims_get(3) LAM/MPI MPI_Graphdims_get(3)
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6 MPI_Graphdims_get - Retrieves graph topology information associated
7 with a communicator
8
10 #include <mpi.h>
11 int MPI_Graphdims_get(MPI_Comm comm, int *pnodes, int *pedges)
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14 comm - communicator for group with graph structure (handle)
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18 pnodes - number of nodes in graph (integer)
19 pedges - number of edges in graph (integer)
20
23 All MPI routines in Fortran (except for MPI_WTIME and MPI_WTICK ) have
24 an additional argument ierr at the end of the argument list. ierr is
25 an integer and has the same meaning as the return value of the routine
26 in C. In Fortran, MPI routines are subroutines, and are invoked with
27 the call statement.
28 All MPI objects (e.g., MPI_Datatype , MPI_Comm ) are of type INTEGER in
30 Fortran.
31
34 If an error occurs in an MPI function, the current MPI error handler is
35 called to handle it. By default, this error handler aborts the MPI
36 job. The error handler may be changed with MPI_Errhandler_set ; the
37 predefined error handler MPI_ERRORS_RETURN may be used to cause error
38 values to be returned (in C and Fortran; this error handler is less
39 useful in with the C++ MPI bindings. The predefined error handler
40 MPI::ERRORS_THROW_EXCEPTIONS should be used in C++ if the error value
41 needs to be recovered). Note that MPI does not guarantee that an MPI
42 program can continue past an error.
43 All MPI routines (except MPI_Wtime and MPI_Wtick ) return an error
45 value; C routines as the value of the function and Fortran routines in
46 the last argument. The C++ bindings for MPI do not return error val‐
47 ues; instead, error values are communicated by throwing exceptions of
48 type MPI::Exception (but not by default). Exceptions are only thrown
49 if the error value is not MPI::SUCCESS .
50 Note that if the MPI::ERRORS_RETURN handler is set in C++, while MPI
53 functions will return upon an error, there will be no way to recover
54 what the actual error value was.
55 MPI_SUCCESS
56 - No error; MPI routine completed successfully.
57 MPI_ERR_TOPOLOGY
58 - Invalid topology. Either there is no topology associated with
59 this communicator, or it is not the correct type (e.g., MPI_CART
60 when expecting MPI_GRAPH ).
61 MPI_ERR_COMM
62 - Invalid communicator. A common error is to use a null commu‐
63 nicator in a call (not even allowed in MPI_Comm_rank ).
64 MPI_ERR_ARG
65 - Invalid argument. Some argument is invalid and is not identi‐
66 fied by a specific error class. This is typically a NULL
67 pointer or other such error.
68
71 For more information, please see the official MPI Forum web site, which
72 contains the text of both the MPI-1 and MPI-2 standards. These docu‐
73 ments contain detailed information about each MPI function (most of
74 which is not duplicated in these man pages).
75 http://www.mpi-forum.org/
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81 The LAM Team would like the thank the MPICH Team for the handy program
82 to generate man pages ("doctext" from ftp://ftp.mcs.anl.gov/pub/sow‐
83 ing/sowing.tar.gz ), the initial formatting, and some initial text for
84 most of the MPI-1 man pages.
85
87 graphdimsget.c
88LAM/MPI 7.1.2 2/23/2006 MPI_Graphdims_get(3)