I feel a bit dumb asking this very basic question, but I have looked and looked but cannot figure it out. Imagine I have a “tree”, in the sense of a container of containers of containers… Such as julia> tree = [[[1,2],[3,4]],[[5,6,7],[8]],[[9,10]]] 3-element Array{Array{Array{Int64,1},1},1}: [[1,…

It can be done with a recursive definition like this: [image] Idiomatic way to write element-wise combination of array of arrays? New to Julia More generally, you can recursively define this broadcast up to any depth n like this julia> function rebroadcast(f,n,args...) …

Thanks @tkf , but I don’t think that is quite what I need. rebroadcast applies f at every level down to n (right?). I want to apply it strictly at level n. But your idea is great. I can do something similar, like julia> mapat(f, t, level) = level == 0 ? f(t) : mapat.(f, t, level-1); julia> mapat(st…

The solution is this I think function MagicMapAtLevel(level,func,tree) if level == 1 return map(func,tree) else for subtree in tree MagicMapAtLevel(level-1,func,subtree) end end end tree = [[[1,2],[3,4]],[[5,6,7],[8]],[[9,10]]] println("level 1") Magi…

If you don’t need the level information you can omit level as parameter. For instance when using arrays with Int64 as base type the function treeMap could have the following form: function treeMap(f, tree) if typeof(tree) == Array{Int64,1} return map(f, tree) else return map( t -> …

The requirement of the OP is to specify a level. For more general solution, maybe I’d go with something like julia> mapover(f, iselement, x) = iselement(x) ? f(x) : map(e -> mapover(f, iselement, e), x) mapover (generic function with 1 method) julia> mapover(string, x -> x isa Number, …

In order to reduce the number of calls and to generalise to more arguments, I’d propose mapat(f, c...; level::Int = 1) = level == 1 ? f.(c...) : level > 1 ? mapat.(f, c..., level = level - 1) : f(c...)

This package GitHub - nlw0/ArrayTrees.jl: ArrayTrees for Julia allows you to map a function to an array-of-arrays. You cannot control the depth of the traversal, but in the OP example, and in many practical situations, the tree has the same depth in every branch, and all the elements at the third le…

Map a function at a given level of a tree

General Usage

tkf August 23, 2019, 10:19pm 2

It can be done with a recursive definition like this:

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Map a function at a given level of a tree

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