Computing e^x element-wise in a NumPy array

In this article, we will discuss how to compute e^x for each element of a NumPy array.

Example :

Input : [1, 3, 5, 7]
Output : [2.7182817, 20.085537, 148.41316, 1096.6332]

Explanation :
e^1 = 2.7182817
e^3 = 20.085537
e^5 = 148.41316
e^7 = 1096.6332

We will be using the numpy.exp() method to calculate the exponential value.

Example 1 :

# importing the module
import numpy as np

# creating an array
arr = np.array([1, 3, 5, 7])
print("Original array: ")
print(arr)

# converting array elements into e ^ x
res = np.exp(arr)
print("\nPrinting e ^ x, element-wise of the said:")
print(res)

Output :

Original array: 
[1 3 5 7]

Printing e ^ x, element-wise of the said:
[   2.71828183   20.08553692  148.4131591  1096.63315843]

Example 2 : We can also find the exponential using the math.exp() method. Although it won’t take the whole NumPy array at once, we have to pass one element at a time.

# importing the module
import numpy as np
import math

# creating an array
arr = np.array([1, 3, 5, 7])
print("Original array: ")
print(arr)

# converting array elements into e ^ x
res = []
for element in arr:
    res.append(math.exp(element))
print("\nPrinting e ^ x, element-wise of the said:")
print(res)

Output :

Original array: 
[1 3 5 7]

Printing e ^ x, element-wise of the said:
[2.718281828459045, 20.085536923187668, 148.4131591025766, 1096.6331584284585]