Ordering of coordinates

With a lot of points vectorial distance can produce quite a large quantity of number crunching.

I do the following to improve the speed of the optimizing program:

Sort the points into strips (the shortest side) (say Y)

Then sort the strips according to the other coordinate. Note that alternative strips must be sorted in ascending and descending sequence. (zig zag across the board)

Points with equal X values should also be sorted for Y.

The number of vectorial calculations are then greatly reduced.

You can stop at the width of the strip or the length to the next point.

It is true that this method sometimes leave almost adjacent points because they are in the next strip, This can be rectified by adjusting the strip.