pbdMPI (version 0.1-5)

sendrecv-method: Send and Receive an Object to and from Other Ranks

Description

This method lets a rank send an object to the other rank and receive an object from another rank in the same communicator. The default return is x.

Usage

sendrecv(x, x.buffer = NULL,
    rank.dest = as.integer((comm.rank(.SPMD.CT$comm) + 1) %%
                           comm.size(.SPMD.CT$comm)),
    send.tag = .SPMD.CT$tag,
    rank.source = as.integer((comm.rank(.SPMD.CT$comm) - 1) %%
                             comm.size(.SPMD.CT$comm)),
    recv.tag = .SPMD.CT$tag,
    comm = .SPMD.CT$comm, status = .SPMD.CT$status)

Arguments

x

an object to be sent from a rank.

x.buffer

a buffer to store x sent from the other rank.

rank.dest

a rank of destination where x send to.

send.tag

a send tag number.

rank.source

a source rank where x sent from.

recv.tag

a receive tag number.

comm

a communicator number.

status

a status number.

Value

• A x is returned by default.

Details

A corresponding sendrecv should be evoked at the corresponding ranks rank.dest and rank.source.

References

Programming with Big Data in R Website: http://r-pbd.org/

See Also

sendrecv.replace.

Examples

# Save code in a file "demo.r" and run with 2 processors by
# > mpiexec -np 2 Rscript demo.r

### Initial
library(pbdMPI, quiet = TRUE)
init()
.comm.size <- comm.size()
.comm.rank <- comm.rank()

### Examples
N <- 5
x <- (1:N) + N * .comm.size
y <- sendrecv(matrix(x, nrow = 1))
comm.print(y, rank.print = 1)

### Finish
finalize()