This package augments the built-in support for histograms with methods that are useful for analyzing large data sets, including a compact Protocol Buffer representation, and routines for merging and manipulating the resulting aggregate histograms.
Eventually, you will be able to install with just:
R > install.packages("HistogramTools", repos = "http://R-Forge.R-project.org").
You can check out the latest source code for this R package with:
$ svn checkout svn://svn.r-forge.r-project.org/svnroot/histogramtools
The project summary page you can find here.