mpi

Class Cartcomm

java.lang.Object

mpi.Comm

mpi.Intracomm

mpi.Cartcomm

public class Cartcomm
extends Intracomm

This class represents a communicator with a cartesian structure.

Field Summary

Fields inherited from class mpi.Comm

handle, MPI_COMM_NULL_VAL

Method Summary

Modifier and Type	Method and Description
Cartcomm	clone() Clones this communicator.
int[]	Coords(int rank) Translate process rank to logical process coordinates.
static void	createDims(int nnodes, int[] dims) Select a balanced distribution of processes per coordinate direction.
int	getRank(int[] coords) Translate logical process coordinates to process rank.
CartParms	getTopo() Returns Cartesian topology information.
int	getTopology() Returns the type of topology associated with the communicator.
int	map(int[] dims, boolean[] periods) Compute an optimal placement.
ShiftParms	shift(int direction, int disp) Compute source and destination ranks for ``shift'' communication.
Cartcomm	sub(boolean[] remain_dims) Partition Cartesian communicator into subgroups of lower dimension.

Methods inherited from class mpi.Intracomm

allGather, allGatherv, allReduce, allToAll, allToAllv, barrier, bcast, create, createCart, createGraph, createGroup, gather, gatherv, nativeGatherv, reduce, reduceScatter, scan, scatter, scatterv, split

Methods inherited from class mpi.Comm

Abort, bSend, bSendInit, compare, create, createIntercomm, deleteAttr, free, getAttr, getGroup, getRank, getSize, ibSend, iProbe, iRecv, irSend, iSend, isInter, isNull, isSend, pack, packSize, probe, recv, recvInit, rSend, rSendInit, send, sendInit, sendRecv, sendRecvReplace, spawn, spawnMultiple, sSend, sSendInit, unpack

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

createDims

public static void createDims(int nnodes,
                              int[] dims)
                       throws MPIException

Select a balanced distribution of processes per coordinate direction.

Parameters:

nnodes - number of nodes in a grid.

dims - array specifying number of nodes in each dimension. Java binding of the MPI operation MPI_DIMS_CREATE. Note that dims is an inout parameter.

Throws:

MPIException - Points out that an MPI exception has occured.

clone

public Cartcomm clone()
               throws MPIException

Clones this communicator.

Java binding of MPI operation MPI_COMM_DUP.

Not Implemented in the current release

.

Overrides:

clone in class Intracomm

Returns:

copy of this communicator. Java binding of the MPI operation MPI_COMM_DUP. The new communicator is ``congruent'' to the old one, but has a different context.

Throws:

MPIException - Points out that an MPI exception has occured.

getRank

public int getRank(int[] coords)
            throws MPIException

Translate logical process coordinates to process rank.

Parameters:

coords - Cartesian coordinates of a process.

Returns:

rank of the specified process.

Java binding of the MPI operation MPI_CART_RANK.

Throws:

MPIException - Points out that an MPI exception has occured.

Coords

public int[] Coords(int rank)
             throws MPIException

Translate process rank to logical process coordinates.

Parameters:

rank - rank of a process.

Returns:

Cartesian coordinates of the specified process.

Java binding of the MPI operation MPI_CART_COORDS.

Throws:

MPIException - Points out that an MPI exception has occured.

shift

public ShiftParms shift(int direction,
                        int disp)
                 throws MPIException

Compute source and destination ranks for ``shift'' communication.

Parameters:

direction - coordinate dimension of shift.

disp - displacement.

Returns:

object containing ranks of source and destination processes.

Java binding of the MPI operation MPI_CART_SHIFT.

Throws:

MPIException - Points out that an MPI exception has occured.

sub

public Cartcomm sub(boolean[] remain_dims)
             throws MPIException

Partition Cartesian communicator into subgroups of lower dimension.

Parameters:

remain_dims - by dimension, true if dimension is to be kept, false otherwise.

Returns:

communicator containing subgrid including this process.

Java binding of the MPI operation MPI_CART_SUB.

Throws:

MPIException - Points out that an MPI exception has occured.

map

public int map(int[] dims,
               boolean[] periods)
        throws MPIException

Compute an optimal placement.

Parameters:

dims - the number of processes in each dimnesion.

periods - true if grid is periodic in each dimension, otherwise false.

Returns:

reordered rank of calling process.

Java binding of the MPI operation MPI_CART_MAP.

The number of dimensions is taken to be size of the dims argument.

Throws:

MPIException - Points out that an MPI exception has occured.

getTopo

public CartParms getTopo()
                  throws MPIException

Returns Cartesian topology information.

Returns:

object containing dimensions, periods and local coordinates.

Java binding of the MPI operations MPI_CARTDIM_GET and MPI_CART_GET.

The number of dimensions can be obtained from the size of (eg) dims field of the returned object.

Throws:

MPIException - Points out that an MPI exception has occured.

getTopology

public int getTopology()
                throws MPIException

Returns the type of topology associated with the communicator.

Not Implemented in the current release

.

Overrides:

getTopology in class Comm

Returns:

topology type of communicator.

Java binding of the MPI operation MPI_TOPO_TEST.

The return value will be one of MPI.GRAPH, MPI.CART or MPI.UNDEFINED.

Throws:

MPIException - Points out that an MPI exception has occured.