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
- 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