A character vector to pass to sleigh via the nodeList argument.
Details
These functions should only be called from an R program that has been
submitted as a parallel batch job by SGE, LSF, or PBS/Torque.
The batchNodeList function calls either sgeNodeList, lsfNodeList, or
pbsNodeList depending on what environment variables are defined.
The resulting list should be passed to the sleigh function via the
nodeList argument.