Julia 1.0 Programming Cookbook

How to do it...

In this recipe, we compare two functions that find all indices of minimal elements in an array. One is simple, but slower; the other is more elaborate, but faster. We compare their outputs and execution speeds:

1. Define a function that finds all indices of minimal elements in an array. Here is how it can be defined:

julia> function allargmin(a)           m = minimum(a)           filter(i -> a[i] == m, eachindex(a))       endallargmin (generic function with 1 method)

2. Test in the Julia command line that it produces the expected results:

julia> allargmin([1,2,3,1,2,3])2-element Array{Int64,1}: 1 4

The result is correct.

3. Define an initial version of the function, finding a random index of a minimum element:

julia> randargmin1(a) = rand(allargmin(a)) ...