[Numpy-discussion] Masked array usage

I have a question about assigning to masked arrays. a is a len ==3 masked array, with 2 unmasked elements. b is a len == 2 array. I want to put the elements of b into the unmasked elements of a. How do I do that? In [598]: a Out[598]: masked_array(data = [1 -- 3], mask = [False True False], fill_value=999999) In [599]: b Out[599]: array([7, 8]) I'd like an operation that gives me: masked_array(data = [7 -- 8], mask = [False True False], fill_value=999999) Seems like it shouldn't be that hard, but I can't figure it out. Any suggestions? thanks, -robert