COMBINATIONS

            //THIS FUNCTION COMBINES A N SIZE SET TO K SIZE SUBSETS 
//WITH OR WITHOUT REPETITION
//JOSE-FERNANDO GIRALDO-J
//2012

//NOTICE THAT THIS FUNCTION IS RECURSIVE AND DOES NOT NEED TO CALCULATE
FACTORIALS


Use:

combine(set,size,repeat)

set: a column vector with elements to combine

size: integer. Defines the size of subsets

repeat: boolean. Defines if elements repetition is allowed in each combination

i.e:

elements=['dog';'cat';'bird';'mouse']

combinations=combine(elements,3,%F)

combinations  =
 
!dog  cat   bird     !
!                    !
!dog  cat   mouse    !
!                    !
!dog  bird  mouse    !
!                    !
!cat  bird  mouse    !


combinations=combine(elements,2,%T)

combinations  =
 
!dog    dog      !
!                !
!dog    cat      !
!                !
!dog    bird     !
!                !
!dog    mouse    !
!                !
!cat    cat      !
!                !
!cat    bird     !
!                !
!cat    mouse    !
!                !
!bird   bird     !
!                !
!bird   mouse    !
!                !
!mouse  mouse    !