Removing nan values from an array
If you're using numpy for your arrays, you can also use
x = x[numpy.logical_not(numpy.isnan(x))]
Equivalently
x = x[~numpy.isnan(x)]
[Thanks to chbrown for the added shorthand]
Explanation
The inner function, numpy.isnan
returns a boolean/logical array which has the value True
everywhere that x
is not-a-number. As we want the opposite, we use the logical-not operator, ~
to get an array with True
s everywhere that x
is a valid number.
Lastly we use this logical array to index into the original array x
, to retrieve just the non-NaN values.
filter(lambda v: v==v, x)
works both for lists and numpy array since v!=v only for NaN
Try this:
import math
print [value for value in x if not math.isnan(value)]
For more, read on List Comprehensions.