Issue #484 <https://github.com/JuliaStats/DataFrames.jl/pull/484> seems to indicate it is on purpose.
On Wednesday, February 5, 2014 3:00:39 PM UTC+2, Christian Groll wrote: > > Since updating DataFrames and DataArrays recently, operators and basic > functions are not working on DataFrames anymore. Is this a new design > decision, or only temporary due to restructuring the code base? > > > julia> Pkg.status() > - DataFrames 0.5.1 > - DataArrays 0.1.1 > > julia> df = DataFrame(rand(4, 2)) > 4x2 DataFrame > |-------|----------|----------| > | Row # | x1 | x2 | > | 1 | 0.698851 | 0.353054 | > | 2 | 0.427287 | 0.76353 | > | 3 | 0.872991 | 0.182744 | > | 4 | 0.779048 | 0.554823 | > > julia> df + 1 > ERROR: no method +(DataFrame, Int64) > > julia> mean(df) > ERROR: no method +((ASCIIString,DataArray{Float64,1}), > (ASCIIString,DataArray{Float64,1})) > in mean at statistics.jl:11 > > julia> df + df > ERROR: no method +(DataFrame, DataFrame) > >