Converting Matlab max to findmax

New to Julia
1

Hi, I’m converting some Matlab code that I’m not very familiar with to Julia, which I’m also not very familiar with, and I’m tripping over myself.

Assume X is a 5 dimensional float64 array of shape 5x6x41x41x18. The following code in Matlab returns 'idxs which is a 1x6x41x41 array:

`[~,idxs] = max(abs(X(1,:,:,:,:)),[],5)`

Which, I believe is the slice that contains the maximum value reduced along the 5th dimension.

My attempt to convert this line to Julia is:

`_, idxs = findmax(abs.(X[1,:,:,:,:]), dims=5)`

However, this returns a 6x41x41x18 array. Clearly not the same, the first dimension is gone and the 5th isn’t reduced.

I must missing something obvious. Any pointers? And thanks.

2

The difference here isn’t in findmax, it’s in the indexing expression. To match Matlab, use X[1:1,:,:,:,:] to keep everything as 5-dimensional or just work with it on dimension 4.

Julia drops all dimensions indexed by scalars, whereas Matlab preserves them (either implicitly or explicitly).

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