A parallel and asynchronous
Reduce for batch systems.
Note that this function only defines the computational jobs.
Each job reduces a certain number of elements on one slave.
The actual computation is started with
Results and partial results can be collected with
batchReduce( fun, xs, init = NULL, chunks = seq_along(xs), more.args = list(), reg = getDefaultRegistry() )
data.table] with ids of added jobs stored in column “job.id”.
batchtools:::example_push_temp(1) # define function to reduce on slave, we want to sum a vector tmp = makeRegistry(file.dir = NA, make.default = FALSE)#>#>xs = 1:100 f = function(aggr, x) aggr + x # sum 20 numbers on each slave process, i.e. 5 jobs chunks = chunk(xs, chunk.size = 5) batchReduce(fun = f, 1:100, init = 0, chunks = chunks, reg = tmp)#>submitJobs(reg = tmp)#>waitForJobs(reg = tmp)#>  TRUE# now reduce one final time on master reduceResults(fun = function(aggr, job, res) f(aggr, res), reg = tmp)#>  5050