[Matplotlib-users] griddata and masked arrays

[ms <dev...@gm...>]

Hi,

I am trying to use griddata to plot some (irregularly) spaced data as a
contour plot, but sometimes ALL the grid it outputs is masked: so no plot.

In the docs I read:
"A masked array is returned if any grid points are outside convex hull
defined by input data (no extrapolation is done)."

but I have no real idea of what does it mean.
Any suggestion to troubleshoot / understand what's going on?

Thanks!

m.