Statistics Toolbox™

combnk - Enumeration of combinations

Syntax

C = combnk(v,k)

C = combnk(v,k) returns all combinations of the n elements in v taken k at a time.

C = combnk(v,k) produces a matrix C with k columns and n! / k!(n-k)! rows, where each row contains k of the elements in the vector v.

It is not practical to use this function if v has more than about 15 elements.

Combinations of characters from a string.

C = combnk('tendril',4);
last5 = C(31:35,:)
last5 =
tedr
tenl
teni
tenr
tend

Combinations of elements from a numeric vector.

c = combnk(1:4,2)
c =
   3   4
   2   4
   2   3
   1   4
   1   3
   1   2