Hello, all. Is there a technical reason that 'meshgrid' and 'mgrid' produce results which differ from each other by a transpose? For example, In [1]: X,Y = meshgrid(array([0,1,2,3]), array([0,1,2,3,4,5])) In [2]: X Out[2]: array([[0, 1, 2, 3], [0, 1, 2, 3], [0, 1, 2, 3], [0, 1, 2, 3], [0, 1, 2, 3], [0, 1, 2, 3]]) In [3]: Y Out[3]: array([[0, 0, 0, 0], [1, 1, 1, 1], [2, 2, 2, 2], [3, 3, 3, 3], [4, 4, 4, 4], [5, 5, 5, 5]]) In [4]: U,V = mgrid[0:4,0:6] In [5]: U Out[5]: array([[0, 0, 0, 0, 0, 0], [1, 1, 1, 1, 1, 1], [2, 2, 2, 2, 2, 2], [3, 3, 3, 3, 3, 3]]) In [6]: V Out[6]: array([[0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5]]) The functions seemed to be designed to do a similar task. It may not seem like a major difference, but it does make for interesting downstream effects, particularly when working with mayavi.mlab. When you call mlab.surf(s) it gets the axes sense correct only if you used mgrid to generate the x-y grid for evaluating s. If you used meshgrid to generate the x-y grid the surface gets rotated in the scene by 90 degrees. Regards, Jed Ludlow