Rclient: Functions to talk to an Rserve

Description

Rserve is a server providing R functionality via sockets. The following functions allow another R session to start new Rserve sessions and evaluate commands. The support is very rudimentary and uses only a fraction of the funtionality provided by Rserve. The typical use of Rserve is to connect to other applications, not necessarily to connect two R processes. However, it is not uncommon to have a cluster of Rserve machines so the following functions provide a simple client access. For more complete cilent implementation see src/clients directory of the Rserve distribution which show a C/C++ client. Also available from the Rserve pages is a Java client (JRclient). See http://rosuda.org/Rserve for details.

Usage

RSconnect(host = "localhost", port = 6311)
RSlogin(c, user, pwd, silent = FALSE)
RSeval(c, cmd)
RSclose(c)
RSdetach(c)
RSevalDetach(c, cmd = "")
RSattach(session)
RSassign(c, obj, name = deparse(substitute(name)) )

Arguments

host

host to connect to

port

TCP port to connect to

Rserve connection

user

username for authentication

pwd

password for authentication

cmd

command (as string) to evaluate

silent

flag indicating whether a failure should raise an error or not

session

session object as returned by RSdetach or RSevalDetach

obj

value to assign

name

name to assign to on the remote side

Details

RSconnect creates a connection to a Rserve. The returned handle is to be used in all subsequent calls to client functions. The session associated witht he connection is alive until closed via RSclose. RSlogin performs authentication with the Rserve. Currently this simple client supports only plain text authentication, encryption is not supported. RSclose closes the Rserve connection. RSeval evaluates the string in the remote Rserve and returns the result. Note that you will have to load the same packages on both ends if the result is an (S3/S4) object such that corresponding classes and methods are available. Also note that the result is transported on the network so sending huge results can be slow. Thus consider sending only relebant parts or keep the results on the other end if pertinent. RSdetach detaches from the current Rserve connection. The connection is closed but can be restored by using RSattach with the value returned by RSdetach. Technically the R on the other end is still running and waiting to be atached. RSevalDetach same as RSdetach but allows asynchronous evaluation of the command. The remote Rserve is instructed to evaluate the command after the connection is detached. Please note that the session cannot be attached until the evaluation finished. Therefore it is advisable to use another session when attaching to verify the status of the detached session where necessary. RSattach resume connection to an existing session in Rserve. The session argument must have been previously returned from the RSdetach or RSevalDetach comment. RSassign pushes an object to Rserve and assigns it to the given name.