If you're using sub or slice, your performance should be vastly better on 0.4
than 0.3, but as you observed it will still be awful. In the long run (maybe
even by the time 0.4 is released?), we hope that in such loops sub/slice won't
actually create a new object and allocate memory---it will be
I have two versions of an example function that calculates a number by
looping over all pair of points. In the first one I use a 2d-array and
access points with [:,i] syntax to get the coordinates. In the second
version of the function I instead creates an array of Point-types (each
Point has a