Julia: readdlm does not support Complex

[dlfivefifty]

This is in 0.6-rc1 (and earlier):

julia> writecsv("/tmp/comp.csv",[1+im])

julia> readcsv("/tmp/comp.csv")
1×1 Array{Any,2}:
 "1 + 1im"

I would expect it to return an Array{Complex{Int},2}.

PS A quick work around is eval.(parse.(readcsv("/tmp/comp.csv")))

[gasagna]

Same for {read, write}dlm.

               _
   _       _ _(_)_     |  A fresh approach to technical computing
  (_)     | (_) (_)    |  Documentation: https://docs.julialang.org
   _ _   _| |_  __ _   |  Type "?help" for help.
  | | | | | | |/ _` |  |
  | | |_| | | | (_| |  |  Version 0.6.1-pre.0 (2017-06-19 13:06 UTC)
 _/ |\__'_|_|_|\__'_|  |  Commit dcf39a1 (64 days old release-0.6)
|__/                   |  x86_64-apple-darwin15.6.0

julia> writedlm("tmp", randn(2, 2) + randn(2, 2)*im)

shell> cat tmp
0.7743929262024812 - 0.3434835979330062im   0.33958454399005045 + 0.28680652862126105im
0.6928954470238671 + 1.597743784536779im    -0.04481314483176969 + 0.48528071828620334im

julia> readdlm("tmp")
2×6 Array{Any,2}:
 0.774393  "-"  "0.3434835979330062im"   0.339585   "+"  "0.28680652862126105im"
 0.692895  "+"  "1.597743784536779im"   -0.0448131  "+"  "0.48528071828620334im"

[ViralBShah]

readdlm is no longer in Base.

[KristofferC]

It's in the stdlib which exists in this repo though?

[StefanKarpinski]

Yeah, until we move things into separate repos, this is still the right place for these issues.

[ViralBShah]

Fair enough. In this case, it isn't even clear if readdlm can or should deal with complex numbers given all the ways one could use whitespace. A CSV file could perhaps be easier to work with.

[gasagna]

@ViralBShah IMO, if Base exposes the capability of writing a complex array to a file using 'writedlm', it should also expose some way to read it.

[ViralBShah]

That is fair enough. I would argue that writedlm should not accept this. CSV.jl or JLD are better unambiguous ways to do this.

[stevengj]

24713 adds readdlm support for Complex{T} (actually requiring less code in DelimitedFiles.jl), though you have to explicitly specify the desired complex type (since the default in readdlm is Float64).