MPI_Group_range_incl(3)            Open MPI            MPI_Group_range_incl(3)



NAME
       MPI_Group_range_incl - Creates a new group from ranges of ranks in an
       existing group.


SYNTAX
C Syntax
       #include <mpi.h>
       int MPI_Group_range_incl(MPI_Group group, int n, int ranges[][3],
            MPI_Group *newgroup)


Fortran Syntax
       INCLUDE 'mpif.h'
       MPI_GROUP_RANGE_INCL(GROUP, N, RANGES, NEWGROUP, IERROR)
            INTEGER   GROUP, N, RANGES(3,*), NEWGROUP, IERROR


C++ Syntax
       #include <mpi.h>
       Group Group::Range_incl(int n, const int ranges[][3]) const


INPUT PARAMETERS
       group     Group (handle).

       n         Number of triplets in array ranges (integer).

       ranges    A one-dimensional array of integer triplets, of the form
                 (first rank, last rank, stride) indicating ranks in group or
                 processes to be included in newgroup.


OUTPUT PARAMETERS
       newgroup  New group derived from above, in the order defined by ranges
                 (handle).

       IERROR    Fortran only: Error status (integer).


DESCRIPTION
       If ranges consist of the triplets

           (first1, last1, stride1), ..., (firstn, lastn, striden)

       then newgroup consists of the sequence of processes in group with ranks

                                                        last(1)-first(1)
         first(1), first(1) + stride(1),..., first(1) + ---------------- stride(1),...
                                                            stride(1)

                                                        last(n)-first(n)
         first(n), first(n) + stride(n),..., first(n) + ---------------- stride(n).
                                                            stride(n)

       Each computed rank must be a valid rank in group and all computed ranks
       must be distinct, or else the program is erroneous. Note that we may
       have first(i) > last(i), and stride(i) may be negative, but cannot be
       zero.

       The functionality of this routine is specified to be equivalent to
       expanding the array of ranges to an array of the included ranks and
       passing the resulting array of ranks and other arguments to
       MPI_Group_incl. A call to MPI_Group_incl is equivalent to a call to
       MPI_Group_range_incl with each rank i in ranks replaced by the triplet
       (i,i,1) in the argument ranges.


NOTE
       This implementation does not currently check to see that the list of
       ranges to include are valid ranks in the group.


ERRORS
       Almost all MPI routines return an error value; C routines as the value
       of the function and Fortran routines in the last argument. C++
       functions do not return errors. If the default error handler is set to
       MPI::ERRORS_THROW_EXCEPTIONS, then on error the C++ exception mechanism
       will be used to throw an MPI:Exception object.

       Before the error value is returned, the current MPI error handler is
       called. By default, this error handler aborts the MPI job, except for
       I/O function errors. The error handler may be changed with
       MPI_Comm_set_errhandler; the predefined error handler MPI_ERRORS_RETURN
       may be used to cause error values to be returned. Note that MPI does
       not guarantee that an MPI program can continue past an error.


SEE ALSO
       MPI_Group_incl
       MPI_Group_free





1.4.1                            Jan 14, 2010          MPI_Group_range_incl(3)
