MPI_SCAN(3)MPI_SCAN(3)NAMEMPI_Scan - Computes the scan (partial reductions) of data on a collection
of processes
SYNOPSIS
C:
#include <mpi.h>
int MPI_Scan ( sendbuf, recvbuf, count, datatype,
op, comm )
void *sendbuf;
void *recvbuf;
int count;
MPI_Datatype datatype;
MPI_Op op;
MPI_Comm comm;
C++:
#include <mpi.h>
void Intracomm::Scan(
const void* sendbuf,
void* recvbuf,
int count,
const Datatype& datatype,
const Op& op) const
Fortran:
INCLUDE "mpif.h" (or USE MPI)
<type> SENDBUF(*), RECVBUF(*)
INTEGER count, datatype, op, comm,
CALL MPI_SCAN(sendbuf, recvbuf, count, datatype, op, comm, ierror)
STANDARDS
This release implements the MPI 1.2 standard, as documented by the MPI
Forum in the spring 1997 release of MPI: A Message Passing Interface
Standard.
The MPI_IN_PLACE option as defined in the MPI 2.0 standard is also
supported in this implementation.
Page 1
MPI_SCAN(3)MPI_SCAN(3)DESCRIPTION
The MPI_Scan routine computes the scan (partial reductions) of data on a
collection of processes. This routine accepts the following parameters:
sendbuf Specifies the starting address of the send buffer (choice).
You may also pass in the argument MPI_IN_PLACE for the value of
sendbuf at all processes. In this case, the input data is
taken from the receive buffer, and replaced by the output data.
Please note that using the MPI_IN_PLACE option in Fortran
causes the receive buffer to become a send-and-receive buffer,
so a binding that includes INTENT must be marked as INOUT, not
OUT.
count Specifies the number of elements in the input buffer (integer)
datatype Specifies the data type of elements of the input buffer
(handle)
op Specifies the operation (handle)
comm Specifies the communicator (handle)
recvbuf Returns the starting address of the receive buffer (choice)
ierror Specifies the return code value for successful completion,
which is in MPI_SUCCESS. MPI_SUCCESS is defined in the mpif.h
file.
Page 2
