core.matrix: How to set all non-zero elements of an array to 1?

[Joachim De Beule]

What would be the best way to to set all non-zero elements of an array to 1 in core matrix?

For 1 dimensional arrays I figured this is a possibility, but I don't know if this is the best way to go:

(m/set-selection doc (m/non-zero-indices doc) 1.0)

For multi-dimensional arrays I could loop over all but one dimension and do something similar, but I'm guessing there should be more efficient ways?

Any advice is welcome!

Joachim

[Mike Anderson]

I would probably use emap to do something something like:

(emap (fn [x] (if (zero? x) 0.0 1.0)) my-array)

emap is more likely to be optimised than something doing a lot of index manipulation, unless your array is very sparse.

Also if it is a mutable array then consider whether you want to change the array in-place or not (with emap! vs. emap)