The first coordinate is the X actually (X0Y0, X0Y1, X0Y2, [...] X2Y0, X2Y1, etc...). In math, the X always represents the first coordinate (abscissa).
If you're not satisfied with the way the "array: for each element" works, simply do your own loops with "System: For" loops.
Have a loop for the Y and the one for the X. Make sure to use correctly the expression "loopindex" with the correct name for your loop.