That's neat! Thanks!
However, it only got me *almost* there - my next step was to use these
arrays as function arguments, so I want to use `...` splatting. However,
`foo([x[y] for x in mytuples,y=1:2]...)` will splat the entire matrix
element-wise, instead of row-wise.
Is there a way to get it into two `Array{Float64,1}` objects, rather than
an `Array{Float64,2}`, and still only use it in one expression?
(Yes, I realize I'm starting to make things more complicated than they need
to be, but this is an opportunity to learn new ways of doing things - not
just an attempt to get things done :P)
// T
On Thursday, July 17, 2014 2:05:38 PM UTC+2, David Gonzales wrote:
>
> it is possible to use two indices in a comprehension:
> mat = [x[y] for x in mytuples,y=1:2]
> now mat[:,1] is your first vector, and mat[:,2] is the second.
>
> On Thursday, July 17, 2014 12:37:20 PM UTC+3, Tomas Lycken wrote:
>>
>> I have an array of 2-tuples of floats, created as
>>
>> julia> mytuples = (Float64,Float64)[(v.x, v.y for v in vs] # slightly more
>> complicated in actual code
>> 136-element Array{(Float64,Float64),1}:
>> (4.0926,-2.55505)
>> (4.170826,-2.586752)
>>
>> ...
>>
>> Now, I’d like to split this into two arrays of floats. I was under the
>> impression that zip could do this for me - according to the docs, zip is
>> its own inverse
>> <http://docs.julialang.org/en/latest/stdlib/base/#Base.zip>, and the
>> array of tuples does look like something I could get from zipping two
>> arrays. So I tried something similar to the example there:
>>
>> julia> julia> [zip(mytuples...)...]
>> 2-element Array{(Float64,Float64,Float64, ... and so on, 136 times...),1}:
>>
>> so I guess that only works on actual Zip objects, and not on arrays
>> (that could have been) generated by the zip function inside []. (Also,
>> since this uses splatting with ... on large lists, it might not be a
>> good idea in the first place…?
>> <https://github.com/JuliaLang/julia/issues/6098#issuecomment-37203821>)
>>
>> What’s the best way to accomplish what I want, i.e. transforming the
>> mytuple variable above into two Vector{Float64}s (possibly inside a
>> tuple or array or something)?
>>
>> // T
>>
>>
>
