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Scilab 6.0.1
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See the recommended documentation of this function

# unique

extracts (and sorts) distinct components of a vector or a matrix

### Syntax

```[N ,k] = unique(M)
[N ,k] = unique(M, orient)```

### Arguments

M

vector or matrix of numbers or strings.

orient

flag with possible values : 1 or "r", 2 or "c"

N

• If `orient` is not used: Vector of extracted `M` components sorted in ascending order.
• If `orient` is used: Matrix of extracted `M` rows or columns, sorted in lexicographic ascending order.

k

Vector of indices of first encountered occurences, such that `N(i) = M(k(i))` or `N(i,:) = M(k(i),:)` or `N(:,i) = M(:,k(i))`.

### Description

`unique(M)` returns a vector which retains the unique entries of `M` in ascending order.

`unique(M,"r")` or `unique(M,1)` removes all duplicates of `M` rows and returns unique rows in lexicographic ascending order.

`unique(M,"c")` or `unique(M,2)` removes all duplicates of `M` columns and returns unique columns in lexicographic ascending order.

 Extracted components, rows or columns can be resorted in their initial order by sorting `k`: ```[N, k] = unique(M); k = gsort(k,"g",i); N = N(k) [N, k] = unique(M, "c"); k = gsort(k,"g",i); N = N(:, k) [N, k] = unique(M, "r"); k = gsort(k,"g",i); N = N(k, :)```

### Examples

```M = round(2*rand(20,1));

unique(M)
[N,k] = unique(M)

unique(string(M))
[N,k] = unique(string(M))

A = [0,0,1,1;
0,1,1,1;
2,0,1,1;
0,2,2,2;
2,0,1,1;
0,0,1,1];
T = 'x'+string(A);

//unique rows

[m,k] = unique(A,'r')
unique(T,'r')

//unique columns
[m,k] = unique(T,'c')
unique(A,'c')```

• members — count (and locate) in an array each element or row or column of another array
• gsort — sorting by quick sort algorithm
• vectorfind — finds in a matrix rows or columns matching a vector
• grep — find matches of a string in a vector of strings
• union — extract union components of a vector
• intersect — returns the vector of common values of two vectors