# unique

Unique values in array

## Syntax

## Description

returns the same data as in `C`

= unique(`A`

)`A`

, but with no repetitions.
`C`

is in sorted order.

If

`A`

is a table or timetable, then`unique`

returns the unique rows in`A`

in sorted order. For timetables,`unique`

takes row times and row values into account when determining whether rows are unique, and sorts the output timetable`C`

by row times.If

`A`

is a categorical array, then the sort order is determined by the order of the categories.

specifies which indices to return in case of repeated values.
`C`

= unique(`A`

,`occurrence`

)`occurrence`

can be `'first'`

(default) or
`'last'`

.

`[`

also returns index vectors `C`

,`ia`

,`ic`

] = unique(___)`ia`

and `ic`

using any of the previous syntaxes.

If

`A`

is a vector, then`C = A(ia)`

and`A = C(ic)`

.If

`A`

is a matrix or array, then`C = A(ia)`

and`A(:) = C(ic)`

.If the

`'rows'`

option is specified, then`C = A(ia,:)`

and`A = C(ic,:)`

.If

`A`

is a table or a timetable, then`C = A(ia,:)`

and`A = C(ic,:)`

.

`[`

,
`C`

,`ia`

,`ic`

]
= unique(`A`

,'legacy')`[`

,
`C`

,`ia`

,`ic`

]
= unique(`A`

,'rows','legacy')`[`

,and
`C`

,`ia`

,`ic`

]
= unique(`A`

,`occurrence`

,'legacy')`[`

preserve the behavior of the `C`

,`ia`

,`ic`

]
= unique(`A`

,'rows',`occurrence`

,'legacy')`unique`

function from R2012b
and prior releases.

The `'legacy'`

option does not support categorical arrays,
datetime arrays, duration arrays, calendarDuration arrays, tables, or
timetables.

## Examples

## Input Arguments

## Output Arguments

## Tips

Use

`uniquetol`

to find unique floating-point numbers using a tolerance.To find unique rows in tables or timetables with respect to a subset of variables, you can use column subscripting. For example, you can use

`unique(A(:,`

, where))`vars`

is a positive integer, a vector of positive integers, a variable name, a cell array of variable names, or a logical vector. Alternatively, you can use`vars`

`vartype`

to create a subscript that selects variables of a specified type.

## Extended Capabilities

## Version History

**Introduced before R2006a**