R: Scatter an array to slaves and then apply a fun

mpi.apply {Rmpi}

R Documentation

Scatter an array to slaves and then apply a fun

Description

An array (length <= total number of slaves) is scattered to slaves so that the first slave calls fun with arguments x[[1]] and ..., the second one calls with arguments x[[2]] and ..., and so on. mpi.iapply is a nonblocking version of mpi.apply so that it will not consume CPU on master node.

Usage

mpi.apply(x, fun, ..., comm=1)  
mpi.iapply(x, fun, ..., comm=1, sleep=0.001)

Arguments

`x`	an array
`fun`	a function
`...`	optional arguments to `fun`
`comm`	a communicator number
`sleep`	a sleep interval on master node (in sec)

Value

A list of the results is returned. Its length is the same as that of x. In case the call fun with arguments x[[i]] and ... fails on ith slave, corresponding error message will be returned in the returning list.

Author(s)

Hao Yu

Examples

## Not run: 
#Assume that there are at least 5 slaves running
#Otherwise run mpi.spawn.Rslaves(nslaves=5)
x=c(10,20)
mpi.apply(x,runif)
meanx=1:5
mpi.apply(meanx,rnorm,n=2,sd=4)

## End(Not run)

[Package Rmpi version 0.5-9 Index]