astropy/astropy — pull request #202 by wkerzendorf (2012-04-16 17:06:28+00:00)
Title: Implementation of errors and masks

To implement arithmetic operation, convolution and interpolation for masks and errors @andycasey and I implemented ndarray subclasses for them. If nothing is specified when instantiating a nddata object it will automatically convert ndarrays to the appropriate mask and error types.