Consider objects a and b, which are array of arrays defined below. These objects are equal according to Julia and the only difference is in how I create them. But double-indexing works very differently on each. julia> a=fill([3,4],2) 2-element Array{Array{Int64,1},1}: [3, 4] [3, 4] julia> b=[[3,…

The issue is not with indexing but at the creation of a : when you use fill([3,4],2), both elements of a point to the same object in memory (here a vector of value [3,4]). You can check that a[1]===a[2] (note the triple = ) whereas b[1] !=== b[2]. Which means that modifying this object will be refle…

Thanks for explaining why this is happening. My overall goal was to create an array with placeholder NaN values using fill, then use a for loop to replace each entry. This would need a fill function that creates copies instead of references (I’m not sure how to accomplish this but it may involve th…

An array comprehension is often a nice way to do this: [[3,4] for _ in 1:2].

See also the somehow related old discussion here … [image] Create initialized arrays of structs General Usage Dearests, today I found a disturbing (yet documented … ) behavior of julia. Let’s see: struct T a::Vector{Int}; end T(N) = T(zeros(Int,N)) Now aiming at a Vect…

Inconsistent behavior with double indexing?

General Usage

Andrea_Pagnani August 23, 2019, 6:14pm 5

See also the somehow related old discussion here …

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Inconsistent behavior with double indexing?

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