SciTools/iris — pull request #286 by ajdawson (2013-01-02 14:18:58+00:00)
Title: NF - normalized area weights

Adds a keyword argument to normalize area weights by the total grid area.

This is actually quite difficult to do after the weights are already returned as the user must compute the sum of weights over only longitude and latitude neglecting other dimensions. It therefore seems best to do this at the time the weights are calculated before they are expanded to the full dimensionality of the cube.