`size`

Size of an array along each dimension.

Category: Language Fundamentals > Matrices and Arrays

Syntax

sz = size(A)

Row vector with the length of every dimension.

n = size(A, dim)

Length along dimension dim.

[r, c, ...] = size(A)

One output per dimension; the last absorbs any remaining dimensions.

sz = size(A, [d1 d2])

Lengths along several chosen dimensions.

Description

A scalar is [1 1], the empty [] is [0 0], and a character vector 'hello' is [1 5]. Asking for a dimension past ndims(A) returns 1.

When there are fewer outputs than dimensions, the last output holds the product of the rest: [r, c] = size(ones(2, 3, 4)) gives r = 2 and c = 12. Use size(A, 1) for rows and size(A, 2) for columns when you need only one number.

Input arguments

A: Array of any type.
dim: Dimension number, or vector of dimension numbers.

Output arguments

sz: Row vector of sizes, at least two elements.
r, c, ...: Sizes as separate scalars.

Example

A = ones(2, 3, 4);
size(A)
size(A, 2)
[r, c] = size(A)

Output

ans = 1×3

     2     3     4
ans = 3
r = 2
c = 12

size