Misleading Terrain Coordinates

Hello, this is not a critical issue but I have found that coordinates in terrain space are quite annoying (Unity 4.0.0f7). Based on my observations I have made a picture:

1121453--42306--$terrain-01.png

My question is: since when X goes along Height and Y along Width? Above all, why the X and Y are swapped in the height map two-dimensional array? I’m not posting this to complain but I want to know whether it’s intentional or justified?

Ok, I have solved the part of mystery and the direction of X,Y and Width,Height is valid (the picture was based on bad calculations). Nevertheless, my mistake came from the swapped X and Y in the two-dimensional array - which I still think is misleading.