Hi, The following is how I usually construct an array. Each element of array temp is an array that has different number of elements (which I assign later). temp = Array{Array{Float64},1}(undef,10) for ii in 1:10 temp[ii] = Float64[] end Is there any way to reduce this code into one line? for e…

You can also initialize as follows if you do not want the sub arrays to be predefined. x = Array{Array{Float64,2},1}(undef,2) x[1] = rand(3,3) x[2] = rand(2,2) push!(x, rand(1,3))# push additional arrays

Use a comprehension. [Float64[] for i in 1:10]

This is great! Thank you so much!

Or, if you want to save a few more characters fill(Float64[], 10) Edit: wrong, see below

This fills the array with 10 references to the same empty array, which probably isn’t what you want. There’s a warning in the docstring about this I believe.

You’re right good catch, I retract my answer. There is indeed a warning about this in the docs.

One follow-up question. [Float64[] for i in 1:10] This gives me a vector of vectors (1-D array). How can I make a vector of 2-D arrays?

Float64[] is an alias for Array{Float64,1}(). So you can use Array{Float64,2}(undef,r,c). It is necessary to specify undef and the dimensions for arrays with more than one dimension. Depending on your use case it might be simpler to use x = [fill(0.0,2,2) for i in 1:10]

Thanks! I appreciate your reply.

Array of arrays construction

General Usage

GunnarFarneback November 14, 2019, 10:19pm 8

Edit: Oh, well, that link is about matrix of vectors, which is interesting but not what was asked here.

See Initialize array of arrays.

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Array of arrays construction

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