Python

# NumPy Np.Rot90()

The NumPy rot90() function allows the rotating of an array by 90 degrees along a specified axis.

Let us discuss.

## Function Syntax

The function syntax is as shown:

 1 numpy.rot90(array, k = 1, axes = (0, 1))

The function parameters are as shown:

1. array – refers to the input array.
2. k – Number of times to rotate the array by 90 degrees.
3. axis – along which axis to rotate the array.

## Return Value

The function returns a copy of the array with the elements rotated along the specified axis by 90 degrees.

## Example #1

The example below shows using the rot90() function with a two-dimensional array.

 1234 # import numpy import numpy as np arr = np.array([[1,2,3], [5,6,7]]) print(np.rot90(arr))

The function will rotate the array along the zero axis and return the array as shown:

 123 [[3 7] [2 6] [1 5]]

## Example #2

To rotate an array along the zero axis by 180 degrees, we can do:

 12 arr = np.array([[1,2,3], [5,6,7]]) print(np.rot90(arr, k=2))

The number of times tells the function to rotate the array along the zero axis by 180 degrees. The above code should return an array as:

 12 [[7 6 5] [3 2 1]]

## Conclusion

This article covered how to rotate an array by 90 degrees along a specified axis using the rot90() function. 