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:

**array**– refers to the input array.**k**– Number of times to rotate the array by 90 degrees.**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.

1 2 3 4 | # 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:

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

## Example #2

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

1 2 | 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:

1 2 | [[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.

Thanks for reading!!