RuntimeWarning: divide by zero encountered in log

Question

I am using numpy.log10 to calculate the log of an array of probability values. There are some zeros in the array, and I am trying to get around it using

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Answer 1

Just use the where argument in np.log10

import numpy as np
np.random.seed(0)

prob = np.random.randint(5, size=4) /4
print(prob)

result = np.where(prob > 0.0000000001, prob, -10)
# print(result)
np.log10(result, out=result, where=result > 0)
print(result)

Output

[1.   0.   0.75 0.75]
[  0.         -10.          -0.12493874  -0.12493874]