[Matplotlib-users] surface plot with masked elements?

[Neal Becker]

I need to make a surface plot where some corner elements of my 2D data are 
invalid, and I'd like to omit them from the plot.

I've seen a couple of stackoverflow questions on the subject, but none of 
the answers seemed satisfactory (or I understood).

It's been some years now, what is the current "best" approach to this 
question?