Iterate over numpy.ma array, ignoring masked values

Question

I would like to iterate over only unmasked values in a np.ma.ndarray.

With the following:

import numpy as np
a = np.ma.array([1, 2, 3], mask = [0, 1, 0])
for i in a:
    print i

I get:

1
--
3

I would like to get the following:

1
3

It seems like np.nditer() may be the way to go, but I don't find any flags that might specify this. How might I do this? Thanks!

Answer 1

you want to use a.compressed()

import numpy as np
a = np.ma.array([1, 2, 3], mask = [0, 1, 0])
for i in a.compressed():
    print i

which gives:

1
3