MATLAB Function Reference    
nchoosek

Binomial coefficient or all combinations

Syntax

Description

C = nchoosek(n,k) where n and k are nonnegative integers, returns n! / ( (n-k)!  k!). This is the number of combinations of n things taken k at a time.

C = nchoosek(v,k), where v is a row vector of length n, creates a matrix whose rows consist of all possible combinations of the n elements of v taken k at a time. Matrix C contains n! / ( (n-k)!  k!) rows and k columns.

Examples

The command nchoosek(2:2:10,4) returns the even numbers from two to ten, taken four at a time:

Limitations

This function is only practical for situations where n is less than about 15.

See Also

perms


 nargoutchk ndgrid