Oh, right, the input vectors are all the same size. It's for a machine learning training set.
I've yet to hit the `hcat(v...)` limit in this particular case. I was just curious to see what the alternatives were, since it seems to be common wisdom that splatting arbitrarily-sized vectors is bad. Thank you for the answers everyone. Cédric On Monday, November 30, 2015 at 1:32:42 AM UTC-5, Tomas Lycken wrote: > > For hcat, what shape would you want the output to have? > > With your example input, the result of vcat is straightforward: > > v = [[1],[2,3],[4,5]] > vcat(v...) > # -> [1, 2, 3, 4, 5] > > But for hcat, what output would you want? hcat(v...) throws a > DimensionMismatch error stating that vectors must have the same length. > //T > > On Friday, November 27, 2015 at 1:39:34 PM UTC+1, Cedric St-Jean wrote: > > foldl would work, but it's going to create a ton of temporary arrays. >> >> None of the proposed efficient solutions work with hcat... I suppose if >> splatting is a problem I should allocate and fill in the array myself. >> >> On Friday, November 27, 2015 at 6:39:07 AM UTC-5, Glen O wrote: >>> >>> Any chance that foldl(vcat,arr_of_arr) will do the job? >>> >>> On Sunday, 22 November 2015 23:04:26 UTC+10, Cedric St-Jean wrote: >>>> >>>> I have a big vector of vectors. Is there any way to vcat/hcat them >>>> without splatting? >>>> >>>> arr_of_arr = Vector[[1],[2,3],[4,5]] >>>> vcat(arr_of_arr...) >>>> >>>> I'm asking because splatting big arrays is a performance issue (and >>>> IIRC it blows the stack at some point). >>>> >>> >
