# rot90

Rotate array 90 degrees

## Syntax

• `B = rot90(A)` example
• `B = rot90(A,k)` example

## Description

example

````B = rot90(A)` rotates array `A` counterclockwise by 90 degrees. For multidimensional arrays, `rot90` rotates in the plane formed by the first and second dimensions.```

example

````B = rot90(A,k)` rotates array `A` counterclockwise by `k*90` degrees, where `k` is an integer.```

## Examples

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### Rotate Column Vector

Create a column vector of sequential elements.

`A = (1:5)'`
```A = 1 2 3 4 5```

Rotate `A` counterclockwise by 90 degrees using `rot90`.

`B = rot90(A)`
```B = 1 2 3 4 5```

The result, `B`, has the same elements as `A` but a different orientation.

### Rotate Multidimensional Array

Create a 3-by-3-by-2 cell array of strings.

`A = cat(3,{'a' 'b' 'c';'d' 'e' 'f';'g' 'h' 'i'},{'j' 'k' 'l';'m' 'n' 'o';'p' 'q' 'r'})`
```A(:,:,1) = 'a' 'b' 'c' 'd' 'e' 'f' 'g' 'h' 'i' A(:,:,2) = 'j' 'k' 'l' 'm' 'n' 'o' 'p' 'q' 'r' ```

Rotate the cell array by 270 degrees.

`B = rot90(A,3)`
```B(:,:,1) = 'g' 'd' 'a' 'h' 'e' 'b' 'i' 'f' 'c' B(:,:,2) = 'p' 'm' 'j' 'q' 'n' 'k' 'r' 'o' 'l'```

The function rotates each page of the array independently. Since a full 360 degree rotation (`k = 4`) leaves the array unchanged, `rot90(A,3)` is equivalent to `rot90(A,-1)`.

## Input Arguments

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### `A` — Input arrayvector | matrix | array | cell array | categorical array

Input array, specified as a vector, matrix, array, cell array, or categorical array of any data type.

Complex Number Support: Yes

### `k` — Rotation constantinteger

Rotation constant, specified as an integer. Specify `k` to rotate by `k*90` degrees rather than nesting calls to `rot90`.

Example: `rot90(A,-2)` rotates `A` by -180 degrees and is equivalent to `rot90(A,2)`, which rotates by 180 degrees.

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