Method of using logarithmic function in numpy

First introduce a constant ee in numpy$e$ is the natural base.

import numpy as np
np.e

Result:

Then we started to use the logarithmic function np.log(). It should be noted that this logarithmic function is based on $The$ logarithmic function with$e$ as the base, that is, this is a natural logarithmic operation.

The natural logarithm log is the inverse of the exponential function,so that log(exp(x)) = x. The natural logarithm is logarithm in base e.

The parameter we input can be a number or an array.

1. Input number:

np.log(1)

Output:

2. Input array:

x=[1,  np.e,  np.e**2,  0]
np.log(x)

Output:

the fourth one represents $-\infty$

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A question is here, what if you want to perform logarithmic function operations with other bases (such as 2, 10)?
Can be achieved indirectly, because there are

${\log }_{m}n=\frac{{\log }_{e}n}{{\log }_{e}m}$

So we define the function as follows:

def log(base,x):
    return np.log(x)/np.log(base)

Then, if we want to calculate ${\log }_{2}8$：

log(2,8)

Output 3, and you're done!