Thanks Eric. Looks good to me. Annoying, but not much to be done, one of the things that happens when moving things to be ufuncs (arguable, the old clip was the issue here).

EDIT: to be clear for the future, the only issue the out argument. clip previously seemingly ignored it on the out array. But if this is wrapped, the masked array is converted to a normal array removing the mask information. With the wrapper the first result should have nothing masked. The wrapper could likely be fixed, but it is not necessary here.

I think you're right, something is fishy with the wrapper. It's probably worth seeing if there are similar problems with the out arguments to other wrappers.

Hmm, wasn't really planning into looking into it, but I guess just because I dislike masked arrays :(. I think the mask should be copied before the operation. But to be honest, things might be tricky, such as needing to handle out=self specifically or so.

I might get around to taking a look