NumPy: Test two arrays are equal (element wise) or not

Last update on December 21 2024 07:51:24 (UTC/GMT +8 hours)

Compare Two Arrays (Element-Wise)

Write a NumPy program to check whether two arrays are equal (element wise) or not.

This problem involves writing a NumPy program to compare two arrays element-wise to determine if they are equal or not. The task requires leveraging NumPy's array comparison functionalities, such as "np.array_equal", which efficiently checks whether the elements in the two arrays match. By comparing the arrays element-wise, the program provides a boolean result indicating whether the arrays are equal or not, facilitating array-based data validation and verification tasks.

Sample Solution :

Python Code :

# Importing the NumPy library with an alias 'np'
import numpy as np

# Creating NumPy arrays 'nums1' and 'nums2' with floating-point values
nums1 = np.array([0.5, 1.5, 0.2])
nums2 = np.array([0.4999999999, 1.500000000, 0.2])

# Setting print options to display floating-point precision up to 15 decimal places
np.set_printoptions(precision=15)

# Printing a message indicating the original arrays 'nums1' and 'nums2'
print("Original arrays:")
print(nums1)
print(nums2)

# Printing a message asking whether the two arrays are equal element-wise or not
print("\nTest said two arrays are equal (element wise) or not:?")
print(nums1 == nums2)

# Reassigning new values to arrays 'nums1' and 'nums2'
nums1 = np.array([0.5, 1.5, 0.23])
nums2 = np.array([0.4999999999, 1.5000000001, 0.23])

# Printing a message indicating the original arrays 'nums1' and 'nums2'
print("\nOriginal arrays:")
np.set_printoptions(precision=15)
print(nums1)
print(nums2)

# Printing a message asking whether the two arrays are equal element-wise or not
print("\nTest said two arrays are equal (element wise) or not:?")
print(np.equal(nums1, nums2))

Output:

Original arrays:
[0.5 1.5 0.2]
[0.4999999999 1.5          0.2         ]

Test said two arrays are equal (element wise) or not:?
[False  True  True]

Original arrays:
[0.5  1.5  0.23]
[0.4999999999 1.5000000001 0.23        ]

Test said two arrays are equal (element wise) or not:?
[False False  True]

Explanation:

The above code shows how to compare two NumPy arrays element-wise for equality using both the == operator and the np.equal() function.

nums1 = np.array(...): This statement creates a NumPy array named 'nums1' containing three float values.

nums2 = np.array(...): This statement creates another NumPy array named 'nums2' containing three float values that are very close to those in 'nums1'.

np.set_printoptions(precision=15): This line sets the printing precision for NumPy arrays to 15 decimal places.

print(nums1 == nums2): This statement compares the two arrays 'nums1' and 'nums2' element-wise using the == operator and prints the resulting boolean array.

nums1 = np.array(...): This statement reassigns 'nums1' to a new NumPy array with slightly different float values.

nums2 = np.array(...): This statement reassigns 'nums2' to a new NumPy array with slightly different float values that are very close to those in 'nums1'.

print(np.equal(nums1, nums2)): This statement compares the two arrays 'nums1' and 'nums2' element-wise using the np.equal() function and prints the resulting boolean array.

Python-Numpy Code Editor: