rot90

Rotate a matrix 90 degrees counter-clockwise.

Syntax

B = rot90(A)
B = rot90(A, k)

Description

Rotates A by 90° counter-clockwise. With the optional integer k, rotates by k * 90° (negative k rotates clockwise). Equivalent to applying flipud(A') for k=1, flipud(fliplr(A)) for k=2, etc.

Examples

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

See also

• fliplr — Flip an array left-to-right (reverse columns).
• flipud — Flip an array upside down (reverse rows).
• circshift — Circularly shift elements of an array.
• permute — Rearrange dimensions of an N-D array.