change the values of an array from nan to zero

Question

I have an array A on python that has some nan values created by numpy.nan. I want to set all the nan values to zero using A[A==numpy.nan] = 0. It doesn't change the array at all. Why is that?

mgilson · Accepted Answer · 2012-11-09 02:39:08Z

11

You want np.isnan:

A[np.isnan(A)] = 0

The problem with your code is that (according to IEEE), nan doesn't equal anything -- even itself.

As a side note, there's also

np.isinf -> (+/- infinity)
np.isfinite -> (not infinity or NaN)
np.isposinf -> (+ infinity)
np.isneginf -> (- infinity)

edited Nov 9, 2012 at 2:39

answered Nov 9, 2012 at 2:27

mgilson

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Cat Over a year ago

Shouldn't np.isfinite say "not infinity or NaN"?

ybdesire · Accepted Answer · 2016-06-20 02:29:11Z

2

You can use the numpy function to change all the nan value at matrix x to zero.

numpy.nan_to_num(x)

answered Jun 20, 2016 at 2:29

ybdesire

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