R: Utilities and Extensions for Foreach Loops

registerDoBackend {NMF} | R Documentation

## Utilities and Extensions for Foreach Loops

### Description

`registerDoBackend` is a unified register function for foreach backends.

`getDoBackend` returns the internal data of the currently registered foreach %dopar% backend.

`setDoBackend` is identical to `setDoPar`, but returns the internal of the previously registered backend.

`register` is a generic function that register objects. It is used to as a unified interface to register foreach backends.

`ForeachBackend` is a factory method for foreach backend objects.

`getDoParHosts` is a generic function that returns the hostname of the worker nodes used by a backend.

`getDoParNHosts` returns the number of hosts used by a backend.

### Usage

      registerDoBackend(object, ...)

      getDoBackend()

      setDoBackend(data, cleanup = FALSE)

      register(x, ...)

      ForeachBackend(object, ...)

      ## S4 method for signature 'doParallel_backend'
    ForeachBackend(object, cl,
        type = NULL)

      ## S4 method for signature 'doPSOCK_backend'
    ForeachBackend(object, cl)

      ## S4 method for signature 'doMPI_backend'
    ForeachBackend(object, cl)

      getDoParHosts(object, ...)

      getDoParNHosts(object)

### Arguments

`object` | specification of a foreach backend, e.g. ‘SEQ’, ‘PAR’ (for doParallel), ‘MPI’, etc...
`...` | extra arguments passed to the backend own registration function.
`data` | internal data of a foreach %dopar% backend.
`cleanup` | logical that indicates if the previous backend's cleanup procedure should be run, before setting the new backend.
`x` | specification of a foreach backend
`cl` | cluster specification: a cluster object or a numeric that indicates the number of nodes to use.
`type` | type of cluster, See `makeCluster`.

### Methods

ForeachBackend

  `signature(object = "ANY")`: Default method defined to throw an informative error message, when no other method was found.

ForeachBackend

  `signature(object = "character")`: Creates a foreach backend object based on its name.

ForeachBackend

  `signature(object = "missing")`: Creates a foreach backend object for the currently registered backend.

ForeachBackend

  `signature(object = "NULL")`: Dummy method that returns `NULL`, defined for correct dispatch.

ForeachBackend

  `signature(object = "cluster")`: Creates a doParallel foreach backend that uses the cluster described in `object`.

ForeachBackend

  `signature(object = "numeric")`: Creates a doParallel foreach backend with `object` processes.

ForeachBackend

  `signature(object = "doParallel_backend")`: doParallel-specific backend factory

ForeachBackend

  `signature(object = "doParallelMC_backend")`: doParallel-specific backend factory for multicore (fork) clusters

  This method is needed since version 1.0.7 of doParallel, which removed internal function `info` and defined separate backend names for mc and snow clusters.

ForeachBackend

  `signature(object = "doParallelSNOW_backend")`: doParallel-specific backend factory for SNOW clusters.

  This method is needed since version 1.0.7 of doParallel, which removed internal function `info` and defined separate backend names for mc and snow clusters.

ForeachBackend

  `signature(object = "doPSOCK_backend")`: doSNOW-specific backend factory

ForeachBackend

  `signature(object = "mpicluster")`: Creates a doMPI foreach backend that uses the MPI cluster described in `object`.

ForeachBackend

  `signature(object = "doMPI_backend")`: doMPI-specific backend factory

getDoParHosts

  `signature(object = "ANY")`: Default method that tries to heuristaically infer the number of hosts and in last resort temporarly register the backend and performs a foreach loop, to retrieve the nodename from each worker.

[Package NMF version 0.21.0 Index]