unique (MATLAB Functions)

Find unique elements of vector

Syntax

b = unique(A)
b = unique(A, 'rows')
[b, m, n] = unique(...)

Description

b = unique(A) returns the same values as in A but with no repetitions. The resulting vector is sorted in ascending order. A can be a cell array of strings.

b = unique(A, 'rows') returns the unique rows of A.

[b, m, n] = unique(...) also returns index vectors m and n such that b = A(m) and A = b(n). Each element of m is the greatest subscript such that b = A(m). For row combinations, b = A(m,:) and A = b(n,:).

Examples

A = [1 1 5 6 2 3 3 9 8 6 2 4]
A =
    1    1    5    6    2    3    3    9    8    6    2    4

[b, m, n] = unique(A)
b =
    1    2    3    4    5    6    8    9
m =
    2   11    7   12    3   10    9    8
n =
    1    1    5    6    2    3    3    8    7    6    2    4

A(m)
ans =
    1    2    3    4    5    6    8    9

b(n)
ans =
    1    1    5    6    2    3    3    9    8    6    2    4

Because NaNs are not equal to each other, unique treats them as unique elements.

unique([1 1 NaN NaN])
ans = 
     1 NaN NaN

See Also

intersect, ismember, issorted, setdiff, setxor, union

union unix