What does np.ma.masked_where function do?

The np.ma.masked_where function in NumPy is used to create a masked array. It masks (hides) elements of an array based on a specified condition. The elements that satisfy the condition are masked, meaning they will not be included in any calculations or visualizations.

Syntax

np.ma.masked_where(condition, a)

condition: A boolean array or condition that determines which elements to mask.
a: The input array from which elements will be masked.

Example

import numpy as np

# Create an array
data = np.array([1, 2, 3, 4, 5])

# Mask elements greater than 3
masked_data = np.ma.masked_where(data > 3, data)

print(masked_data)

Output

[1 2 3 -- --]

In this example, the elements greater than 3 are masked (represented by --), while the others remain visible.