1MPI_Cart_create(3) LAM/MPI MPI_Cart_create(3)
2
6 MPI_Cart_create - Makes a new communicator to which topology informa‐
7 tion has been attached
8
10 #include <mpi.h>
11 int MPI_Cart_create(MPI_Comm comm, int ndims, int *dims,
12 int *periods, int reorder, MPI_Comm *pnewcomm)
13
15 comm - input communicator (handle)
16 ndims - number of dimensions of cartesian grid (integer)
17 dims - integer array of size ndims specifying the number of processes
18 in each dimension
19 periods
20 - logical array of size ndims specifying whether the grid is
21 periodic (true) or not (false) in each dimension
22 reorder
23 - ranking may be reordered (true) or not (false) (logical)
24
27 pnewcomm
28 - communicator with new cartesian topology (handle)
29
32 LAM/MPI currently ignores the reorder flag.
33
36 All MPI routines in Fortran (except for MPI_WTIME and MPI_WTICK ) have
37 an additional argument ierr at the end of the argument list. ierr is
38 an integer and has the same meaning as the return value of the routine
39 in C. In Fortran, MPI routines are subroutines, and are invoked with
40 the call statement.
41 All MPI objects (e.g., MPI_Datatype , MPI_Comm ) are of type INTEGER in
43 Fortran.
44
47 If an error occurs in an MPI function, the current MPI error handler is
48 called to handle it. By default, this error handler aborts the MPI
49 job. The error handler may be changed with MPI_Errhandler_set ; the
50 predefined error handler MPI_ERRORS_RETURN may be used to cause error
51 values to be returned (in C and Fortran; this error handler is less
52 useful in with the C++ MPI bindings. The predefined error handler
53 MPI::ERRORS_THROW_EXCEPTIONS should be used in C++ if the error value
54 needs to be recovered). Note that MPI does not guarantee that an MPI
55 program can continue past an error.
56 All MPI routines (except MPI_Wtime and MPI_Wtick ) return an error
58 value; C routines as the value of the function and Fortran routines in
59 the last argument. The C++ bindings for MPI do not return error val‐
60 ues; instead, error values are communicated by throwing exceptions of
61 type MPI::Exception (but not by default). Exceptions are only thrown
62 if the error value is not MPI::SUCCESS .
63 Note that if the MPI::ERRORS_RETURN handler is set in C++, while MPI
66 functions will return upon an error, there will be no way to recover
67 what the actual error value was.
68 MPI_SUCCESS
69 - No error; MPI routine completed successfully.
70 MPI_ERR_COMM
71 - Invalid communicator. A common error is to use a null commu‐
72 nicator in a call (not even allowed in MPI_Comm_rank ).
73 MPI_ERR_TOPOLOGY
74 - Invalid topology. Either there is no topology associated with
75 this communicator, or it is not the correct type (e.g., MPI_CART
76 when expecting MPI_GRAPH ).
77 MPI_ERR_DIMS
78 - Illegal dimension argument. A dimension argument is null or
79 its length is less than or equal to zero.
80 MPI_ERR_ARG
81 - Invalid argument. Some argument is invalid and is not identi‐
82 fied by a specific error class. This is typically a NULL
83 pointer or other such error.
84
87 For more information, please see the official MPI Forum web site, which
88 contains the text of both the MPI-1 and MPI-2 standards. These docu‐
89 ments contain detailed information about each MPI function (most of
90 which is not duplicated in these man pages).
91 http://www.mpi-forum.org/
93
97 The LAM Team would like the thank the MPICH Team for the handy program
98 to generate man pages ("doctext" from ftp://ftp.mcs.anl.gov/pub/sow‐
99 ing/sowing.tar.gz ), the initial formatting, and some initial text for
100 most of the MPI-1 man pages.
101
103 cartcreate.c
104LAM/MPI 7.1.2 2/23/2006 MPI_Cart_create(3)