## 27 Sets

Octave has a limited set of functions for managing sets of data, where a set is defined as a collection unique elements.

— Function File: create_set (x)

> Return a row vector containing the unique values in x, sorted in ascending order. For example,

>               create_set ([ 1, 2; 3, 4; 4, 2 ])
>               => [ 1, 2, 3, 4 ]

— Function File: union (x, y)

> Return the set of elements that are in either of the sets x and y. For example,

>               union ([ 1, 2, 4 ], [ 2, 3, 5 ])
>               => [ 1, 2, 3, 4, 5 ]

— Function File: intersection (x, y)

> Return the set of elements that are in both sets x and y. For example,

>               intersection ([ 1, 2, 3 ], [ 2, 3, 5 ])
>               => [ 2, 3 ]

— Function File: complement (x, y)

> Return the elements of set y that are not in set x. For example,

>               complement ([ 1, 2, 3 ], [ 2, 3, 5 ])
>               => 5