Combin2Rank

Calculates the rank (sequential ordinal) of nCk combinations

Description

Example:

Combs=nchoosek(1:5,3)
Combs =
     1 2 3
     1 2 4
     1 2 5
     1 3 4
     1 3 5
     1 4 5
     2 3 4
     2 3 5
     2 4 5
     3 4 5
Combin2Rank(5,3,Combs)
ans =
     1
     2
     3
     4
     5
     6
     7
     8
     9
    10

ref: A Numbering System for Combinations, Gary D. Knott, Communications of the ACM, Jan. 1974, v.17, n.1

• MATLAB release: MATLAB 7.6 (R2008a)