JuliaStats/DataFrames.jl — pull request #354 by nfoti (2013-08-22 06:40:34+00:00)
Title: WIP: Operations for DataArray that skip NA values

I've implemented a few operations on `DataArrays` that can skip `NA` values. This behavior can eventually be tied to a flag to turn it on or off, but for now I just wanted to get something working. I've implemented the approach outlined by @simonster in Issue #325 using the `NumericalExtenstions` package.