Max & Min of NumPy Array in Python (3 Examples)

In this tutorial, I’ll illustrate how to calculate the maximum and minimum of a NumPy array in the Python programming language.

Table of contents:

Let’s dive right into the examples.

Example Data & Libraries

If we want to use the functions of the NumPy library, we first need to import NumPy:

import numpy as np                             # Import NumPy library in Python

Next, we’ll also need to construct some example data:

my_array = np.array([[1, 2, 3], [4, 5, 6]])    # Create example array
print(my_array)                                # Print example array
# [[1 2 3]
#  [4 5 6]]

The previous output of the Python console shows the structure of our example data: We have created a NumPy array with six values in two rows and three columns.

Example 1: Max & Min of All Values in NumPy Array

In this example, I’ll illustrate how to get the minima and maxima of all values in a NumPy array.

To calculate the maximum value, we can use the np.max function as shown below…

print(np.max(my_array))                        # Get max of all array values
# 6

…and to compute the minimum value, we can apply the min function as illustrated in the following Python code:

print(np.min(my_array))                        # Get min of all array values
# 1

Example 2: Max & Min of Columns in NumPy Array

Example 2 shows how to find the max and min values of a NumPy array by columns.

For this task, we have to set the axis argument to be equal to 0:

print(np.max(my_array, axis = 0))              # Get max of array columns
# [4 5 6]

print(np.min(my_array, axis = 0))              # Get min of array columns
# [1 2 3]

As you can see, the previous Python codes have returned the maximum and minimum of our NumPy array by column.

Example 3: Max & Min of Rows in NumPy Array

In this example, I’ll show how to compute the row-wise maxima and minima of a NumPy array.

Similar to Example 2, we can use the axis argument for this task. However, this time, we have to set the axis argument to 1:

print(np.max(my_array, axis = 1))              # Get max of array rows
# [3 6]

print(np.min(my_array, axis = 1))              # Get min of array rows
# [1 4]

Video & Further Resources

I have recently released a video on the Statistics Globe YouTube channel, which illustrates the Python programming code of this article. Please find the video below:

Furthermore, you could read the related tutorials on my homepage. You can find some posts below.

• Max & Min in Python
• Max & Min by Group in Python
• Convert pandas DataFrame to NumPy Array in Python
• Get Max & Min Value of Column & Index in pandas DataFrame in Python
• Convert pandas DataFrame Index to List & NumPy Array in Python
• Get Median of Array with np.median Function of NumPy Library in Python
• Python Programming Examples

To summarize: In this post, I have demonstrated how to find the maximum and minimum of a NumPy array in Python. In case you have additional questions, tell me about it in the comments below.