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permsk

version 1.1 (1.77 KB) by Jos (10584)
All permutations of K elements from an array (set)

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Updated 22 Apr 2019

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P = permsk(S, K) returns all permutations of K elements taken from the set S with N elements. P will be a N!/(N-K)!-by-K array. Each row of P holds a unique permutation of K elements.
P will be of the same type as S, which can be any kind of array (numerical, char, string, struct, cell, etc.).

Example:
permsk(1:4, 2) % -> [ 1 2 ; 1 3 ; 1 4 ; 2 1 ; ...
... 3 2 ; 3 4 ; 4 1 ; 4 2 ; 4 3]

The list of permutations in the rows of P are ordered. To speed things up slightly, you can provide a third argument, like: permsk(S, K, 1), so a call to sortrows is skipped.
When K > N, P will be empty.

See also perms, nchoosek, randperm, permute.
permn, nchoose, nchoose2 (file Exchange)

Cite As

Jos (10584) (2021). permsk (https://www.mathworks.com/matlabcentral/fileexchange/71300-permsk), MATLAB Central File Exchange. Retrieved .

MATLAB Release Compatibility
Created with R2019a
Compatible with any release
Platform Compatibility
Windows macOS Linux

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