Me and @pedrohasselmann found a strange issue when using numpy.meshgrid for 3 dimensions and higher. The axis of each grid are shuffled and are not returned in the same order in which they were given.

The docs at http://docs.scipy.org/doc/numpy/reference/generated/numpy.meshgrid.html present the wrong order for nx and ny in the loop for the example. It says xv, yv ...