Hi all,

maybe I've misunderstood something concerning masking or quiver plots:

I want to exclude some data from a quiver plot. Here's an example:

--------------------8<----

import numpy as N

import pylab as pl

import matplotlib.numerix.ma as ma

# prepare data

X,Y = pl.meshgrid(range(5),range(5))

angles = pl.rand(5,5)

U = N.cos(angles)

V = N.sin(angles)

# prepare mask

M = N.zeros((5,5), dtype='bool')

M[2,2] = True

# apply mask

Um = ma.masked_array(U,mask=M)

Vm = ma.masked_array(V,mask=M)

# plot

pl.quiver(X,Y,Um,Vm)

# pl.plot(range(5),Um[2],'x')

pl.show()

---------------------->8----

Using the commented 'plot' command works as expected, but 'quiver' results in

empty axes. If I take U,V instead of Um,Vm, the arrows are drawn ..

What am I doing wrong or is there another way to exclude arrows from being

plotted?

Thank you in advance,

Michael