# ismember

Determine which elements of the first argument exist in the second argument.

## Syntax

ismember(x,s)

ismember(x,s,'rows')

[bool, index] = ismember(...)

## Inputs

`x`- Type: double | integer | char | string | logical | struct | cell
`s`- The items from which to find possible matches.
`'rows'`- Specify that the search be made for common rows as opposed to common elements.

## Outputs

- bool
- A matrix with the same dimenions as
`x`, with each element set to 1 if the corresponding element of`x`is contained in`s`, and 0 otherwise. - index
- A matrix with the same dimenions as
`x`that contains indices of s(:) for the matched elements reported in bool, and 0 otherwise.

## Examples

Matrix example:

`[bool, index] = ismember([5 4; 3 6],[7 5 8 9 6])`

`bool = [Matrix] 2 x 2
1 0
0 1
index = [Matrix] 2 x 2
2 0
0 5`

String example:

`[bool, index] = ismember('abcd','baeg')`

`bool = [Matrix] 1 x 4
1 1 0 0
index = [Matrix] 1 x 4
2 1 0 0`

Row example:

`ismember([1 2 3; 1 4 5; 1 2 3],[1 2 3],'rows')`

`ans = [Matrix] 3 x 1
1
0
1`