DavW/crunch-lib — pull request #1 by DavW (2014-11-12 14:45:11+00:00)
Title: Averages.meanValue(PTable<K, V extends Numeric>) implementation

Calculating the mean value for each key in a table is somewhat fiddly to implement
and users may also roll their own interpretations which perform badly (for example
by reducing twice or loading reduce set into memory). We will therefore provide a
convenient library implementation.