astropy/astropy — pull request #500 by mdboom (2012-11-26 17:31:39+00:00)
Title: Unit.to does not respected np.ma.MaskedArray

Hi @perrygreenfield, @mdboom I just discovered while updating `NDData`'s arithmetic to reflect a `Quantity` like behaviour that the `Unit.to` function changes an input `MaskedArray` into a normal array. Could you fix this? Cheers