NumPy Logs
Logs
NumPy provides functions to perform log at the base 2, e and 10.
We will also explore how we can take log for any base by creating a custom ufunc.
All of the log functions will place -inf or inf in the elements if the log can not be computed.
Log at Base 2
Use thelog2() function to perform log at the base 2.
Example
Find log at base 2 of all elements of following array:
arr = np.arange(1, 10)
print(np.log2(arr))
Note: Thearange(1, 10) function returns an array with integers starting from 1 (included) to 10 (not included).
Log at Base 10
Use thelog10() function to perform log at the base 10.
Example
Find log at base 10 of all elements of following array:
arr = np.arange(1, 10)
print(np.log10(arr))
Natural Log, or Log at Base e
Use thelog() function to perform log at the base e.
Example
Find log at base e of all elements of following array:
arr = np.arange(1, 10)
print(np.log(arr))
Log at Any Base
NumPy does not provide any function to take log at any base,so we can use thefrompyfunc() function along with inbuilt functionmath.log() with two input parameters and one output parameter:
Example
import numpy as np
nplog = np.frompyfunc(log, 2, 1)
print(nplog(100, 15))
