batchReduce: Reduces via a binary function over a list adding jobs to a...
In BatchJobs: Batch Computing with R

batchReduce

R Documentation

Reduces via a binary function over a list adding jobs to a registry.

Description

Each jobs reduces a certain number of elements on one slave. You can then submit these jobs to the batch system.

Usage

batchReduce(reg, fun, xs, init, block.size, more.args = list())

Arguments

`reg`	[`Registry`] Empty Registry.
`fun`	[`function(aggr, x, ...)`] Function to reduce `xs` with.
`xs`	[`vector`] Vector to reduce.
`init`	[any] Initial object for reducing.
`block.size`	[`integer(1)`] Number of elements of `xs` reduced in one job.
`more.args`	[`list`] A list of other arguments passed to `fun`. Default is empty list.

Value

Vector of type integer with job ids.

Examples

# define function to reduce on slave, we want to sum a vector
f = function(aggr, x) aggr + x
reg = makeRegistry(id = "BatchJobsExample", file.dir = tempfile(), seed = 123)

# sum 20 numbers on each slave process, i.e. 5 jobs
batchReduce(reg, fun = f, 1:100, init = 0, block.size = 5)
submitJobs(reg)
waitForJobs(reg)

# now reduce one final time on master
reduceResults(reg, fun = function(aggr,job,res) f(aggr, res))

BatchJobs documentation built on March 21, 2022, 5:05 p.m.