`rot90`

Rotates a matrix by multiples of 90 degrees.

Category: Language Fundamentals > Matrices and Arrays

Syntax

B = rot90(A)

Rotates 90 degrees counterclockwise.

B = rot90(A, k)

Rotates k*90 degrees; negative k turns clockwise.

Description

The first row of A ends up as the first column of B, read from bottom to top, after one counterclockwise turn. Only k modulo 4 matters. For a half turn use rot90(A, 2), which equals flip(flip(A, 1), 2).

Input arguments

A: Array of any type.
k: Integer number of quarter turns (default 1).

Output arguments

B: Rotated array. For odd k its rows and columns are swapped.

Example

A = [1 2; 3 4];
rot90(A)
rot90(A, -1)
rot90(A, 2)

Output

rot90