I have an array of type Array{Float64,2} but it's an array of 1 column, and I'm unable to pass this into a function that's expecting a single-column array of type Array{Float64,1}. I don't really understand what the 2 means or how to fix my problem, and I haven't been able to figure it out by searching through any documentation.
4
votes
1 Answers
5
votes
In Array{Float64,2}, the 2 is the number of dimensions in the array. Since you say it's "it's an array of 1 column", you probably have something which is 2-dimensional with either one row or one column, i.e. one of
julia> c = rand(1,3)
1x3 Array{Float64,2}:
0.190944 0.928697 0.251519
julia> d = rand(3,1)
3x1 Array{Float64,2}:
0.0818493
0.0342291
0.58341
To turn this into a 1-dimensional array, you could slice the array manually or use squeeze, as you prefer:
julia> c[1,:]
3-element Array{Float64,1}:
0.190944
0.928697
0.251519
julia> squeeze(d,2)
3-element Array{Float64,1}:
0.0818493
0.0342291
0.58341
Either approach should give you something of type Array{Float64,1}.
As noted in the comments, another approach is to use reshape, e.g. (using a different random c):
julia> reshape(c, length(c))
3-element Array{Float64,1}:
0.680653
0.0573147
0.607054
This has the advantage -- and disadvantage -- of not caring whether you have an array of shape 1xN or Nx1.
