This is quite close to being possible, but we’re missing a few things. Daniel Jones recently added an append! method to DataArrays, which would let you do this column-by-column.
To help you out, we need to add an append! method to DataFrames as well. I’ve wanted that badly myself lately. I will try to get to this today, but am already pretty overwhelmed with work for the day. — John On Jan 26, 2014, at 11:02 AM, Joosep Pata <joosep.p...@gmail.com> wrote: > Is there a way to avoid copying when doing vcat(df1::DataFrame, > df2::DataFrame, …)? I’m trying to open hundreds of files with DataFrames, > merge all of them and save a single ~150M row x 100 col DataFrame using HDF5 > and JLD (to be opened later using mmap), and it seems to work marvelously, > apart from the vcat. > Does a no-copy option exist? I’m aware of DataStreams as a concept, but as I > understand, they’re not fully fleshed out yet.
