Bug report

As described in#11663 (review):

Something funny is going on here (I know it was already there before, but still seems worth pointing out): we take x and y of any shapes and flatten them (they just need to have the same size), butc has to match either the shape ofx ory, not just the size.

In other words the following "work" (i.e. perform an implicit ravel()):

scatter(np.arange(12).reshape((3, 4)), np.arange(12).reshape((4, 3)), c=np.arange(12).reshape((3, 4)))scatter(np.arange(12).reshape((3, 4)), np.arange(12).reshape((4, 3)), c=np.arange(12).reshape((4, 3)))

but the following fail:

scatter(np.arange(12).reshape((3, 4)), np.arange(12).reshape((4, 3)), c=np.arange(12).reshape((6, 2)))# and evenscatter(np.arange(12).reshape((3, 4)), np.arange(12).reshape((4, 3)), c=np.arange(12))

Of course that last one has the best error message (irony intended):

ValueError: 'c' argument has 12 elements, which is not acceptable for use with 'x' with size 12, 'y' with size 12.