Example 1: Assessing the Robustness of the One-Sample t-test

Many scientific computations can be sped up by dividing them into smaller tasks and distributing the computations to multiple systems for simultaneous processing. Such a process is referred to as parallel computing. When performed on existing grids of computers, this method can dramatically decrease computation time. Several solutions exist to facilitate this type of computation within R, and we describe one such solution here, that involves using the Apple Xgrid (Apple, 2009), a parallel computing environment. We created the xgrid package to provide a simple interface to this distributed computing system (Horton et al., 2011). The package facilitates use of an Apple Xgrid for distributed processing of a job with many independent repetitions, by simplifying task submission (or gridstuffing) and collation of results. We demonstrate use of our package in the context of a real, although relatively simple, statistical problem.