# size

size of objects

## Calling Sequence

                sz = size(x)
                [n1, n2] = size(x)
                [n1, n2, n3, ...] = size(x)
                n = size(x, sel)

## Arguments

x

  a 2-D or n-D array of any type or a list

sz

  `1` by ndims(x) integer vector.

sel

  a positive scalar with integer value or one of the character strings 'r', 'c' or '*'

n1, n2, ...

  numbers with integer values

n

  a number with integer value

## Description

Applied to :

  an array or n-D array (constant, polynomial, string, boolean, rational)

  - `sz = size(x)` returns a `1`-by-`ndims(x)` vector. Each entry gives the corresponding dimension value.
  - `[n1, n2, ...] = size(x)`, the function returns in each argument the corresponding dimension value.
  - The syntax `n = size(x, sel)` may be used to specify what dimension to get:

    - Set `sel` to 1 or `'r'` to get the number of rows.
    - Set `sel` to 2 or `'c'` to get the number of columns.
    - Set `sel` to `m`, where `m` is a positive integer to get the `m`th dimension. If `m` is greater than `ndims(x)`, then `size(x,m)` returns 1.
    - Set `sel` to `'*'` to get the product of the dimensions.
Applied to:

  a list; it returns the number of elements. In this case only `y = size(x)` syntax can be used.

Applied to:

  a linear system; `y= size(x)` returns in `y` the (row) vector [number of outputs, number of inputs] i.e. the dimension of the corresponding transfer matrix. The syntax `[nr, nc] = size(x)` is also valid (with `(nr, nc) = (y(1), y(2))`). If `x` is a linear system in state-space form, then `[nr, nc, nx] = size(x)` returns in addition the dimension `nx` of matrix `x`.

## Examples

                [n, m] = size(rand(3, 2))
                [n, m] = size(['a', 'b'; 'c', 'd'])

                x = ssrand(3, 2, 4);
                [ny, nu] = size(x)
                [ny, nu] = size(ss2tf(x))
                [ny, nu, nx] = size(x)

                // Returns the number of rows
                n = size(rand(3, 2), "r")
                // Returns the number of columns
                m = size(rand(3, 2), "c")
                // Returns the product of the dimensions
                nm = size(rand(3, 2), "*")

## See Also

- length
- ndims
- syslin