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How to Map a Function Over NumPy Array?

In this tutorial, we will learn how to map a function over NumPy array? By Pranit Sharma Last updated : May 23, 2023

To map a function over NumPy array, the numpy.vectorize() method is used by passing a lambda expression in it.

The following is the syntax of the numpy.vectorize() method:

class numpy.vectorize(pyfunc, otypes=None, doc=None, excluded=None, cache=False, signature=None)

Let us understand with the help of an example,

Python Program to Map a Function Over NumPy Array

# Import numpy
import numpy as np

# Creating a numpy array
arr = np.array([1, 2, 3, 4, 5])

# Display Original Array
print("Original Array:\n",arr,"\n")

# writing an expression
exp = lambda x: x ** 2

# Using numpy.vectorize
res = np.vectorize(exp)

# Call vectorized result
res = res(arr)

# Display Result
print('Result:\n',res)

Output

Original Array:
 [1 2 3 4 5] 

Result:
 [ 1  4  9 16 25]
 

Output (Screenshot)

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