[Matplotlib-users] strange behavior using a mask with Basemap

[Yeates, M. C (388D) <mat...@jp...>]

Hi
I would expect
hgt=ma.masked_where(div == 0,hgt)
m.contourf(x,y,hgt,15,cmap=plt.cm.jet)

to produce a map complementary to the map produced by

hgt=ma.masked_where(div != 0,hgt)
m.contourf(x,y,hgt,15,cmap=plt.cm.jet)

But, this is not the case.
What am I missing?

Mathew