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MPI_Group_range_incl - Creates a new group from ranges of ranks
in an existing group.
#include <mpi.h>
int MPI_Group_range_incl(MPI_Group group, int n, int ranges[][3],
MPI_Group *newgroup)
USE MPI
! or the older form: INCLUDE ’mpif.h’
MPI_GROUP_RANGE_INCL(GROUP, N, RANGES, NEWGROUP, IERROR)
INTEGER GROUP, N, RANGES(3,*), NEWGROUP, IERROR
USE mpi_f08
MPI_Group_range_incl(group, n, ranges, newgroup, ierror)
TYPE(MPI_Group), INTENT(IN) :: group
INTEGER, INTENT(IN) :: n, ranges(3,n)
TYPE(MPI_Group), INTENT(OUT) :: newgroup
INTEGER, OPTIONAL, INTENT(OUT) :: ierror
- 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.
- newgroup
- New group derived
from above, in the order defined by ranges (handle).
- IERROR
- Fortran only:
Error status (integer).
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.
This implementation
does not currently check to see that the list of ranges to include are
valid ranks in the group.
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.
MPI_Group_incl
MPI_Group_free
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