Figure Properties - SERC

nchoosek
2nchoosek
Purpose Binomial coefficient or all combinations
Syntax C = nchoosek(n,k)
C = nchoosek(v,k)
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.
2-1518
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:
2 4 6 8
2 4 6 10
2 4 8 10
2 6 8 10
4 6 8 10
Limitations This function is only practical for situations where n is less than about 15.
See Also perms