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Logarithm of the sum of exponentiations of the inputs in Numpy
To get the Logarithm of the sum of exponentiations of the inputs, use the numpy.logaddexp() method in Python Numpy.
Calculate log(exp(x1) + exp(x2)). This function is useful in statistics where the calculated probabilities of events may be so small as to exceed the range of normal floating-point numbers. In such cases the logarithm of the calculated probability is stored. This function allows adding probabilities stored in such a fashion.
NumPy offers comprehensive mathematical functions, random number generators, linear algebra routines, Fourier transforms, and more. It supports a wide range of hardware and computing platforms, and plays well with distributed, GPU, and sparse array libraries.
Steps
At first, import the required library −
import numpy as np
Log input −
one = np.log(1e-50) two = np.log(2.5e-50)
# Display the log input −
print("Value 1...
", one)
print("Value 2...
", two)To get the Logarithm of the sum of exponentiations of the inputs, use the numpy.logaddexp() method in Python Numpy −
res = np.logaddexp(one, two)
print("
Logarithm of the sum of exponentiations...
",res)Example
import numpy as np
# Calculates log(exp(x1) + exp(x2)).
# This function is useful in statistics where the calculated probabilities
# of events may be so small as to exceed the range of normal floating point numbers.
# In such cases the logarithm of the calculated probability is stored.
# This function allows adding probabilities stored in such a fashion.
# Log input
one = np.log(1e-50)
two = np.log(2.5e-50)
# Display the log input
print("Value 1...
", one)
print("Value 2...
", two)
# To get the Logarithm of the sum of exponentiations of the inputs, use the numpy.logaddexp() method in Python Numpy
res = np.logaddexp(one, two)
print("
Logarithm of the sum of exponentiations...
",res)Output
Value 1... -115.12925464970229 Value 2... -114.21296391782813 Logarithm of the sum of exponentiations... -113.87649168120691
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