A set of tools that solves a common set of problems: you need to break a big
problem down into manageable pieces, operate on each piece and then put all the
pieces back together. For example, you might want to fit a model to each
spatial location or time point in your study, summarise data by panels or
collapse high-dimensional arrays to simpler summary statistics. The development
of plyr has been generously supported by Becton Dickinson.
