NCHOOSE3 - all combinations of three elements

Y = NCHOOSE3(X) returns all combinations of three elements of the array X. It is the fast, vectorized version of NCHOOSEK(X,3). X can be any type of array. When X is a scalar integer > 1, it returns X*(X-1)*(X-2)/6.

Example:

nchoose3([10 20 30 40 50])
->    10    20    30
      10    20    40
      10    20    50
      10    30    40
      10    30    50
      10    40    50
      20    30    40
      20    30    50
      20    40    50
      30    40    50

nchoose3({'a','b','c','d','e'})
->  {'a'}    {'b'}    {'c'}
    {'a'}    {'b'}    {'d'}
    {'a'}    {'b'}    {'e'}
    {'a'}    {'c'}    {'d'}
    {'a'}    {'c'}    {'e'}
    {'a'}    {'d'}    {'e'}
    {'b'}    {'c'}    {'d'}
    {'b'}    {'c'}    {'e'}
    {'b'}    {'d'}    {'e'}
    {'c'}    {'d'}    {'e'}

See also NCHOOSEK, PERMS, NEXTPERM NCHOOSE2, PERMN, NCHOOSE, ALLCOMB (on the File Exchange)

version 1.0 (Wednesday, 12. December 2018) (c) Sebastian J. Schlecht https://www.sebastianjiroschlecht.com/

Heavily inspired by NCHOOSE2 by (c) Jos van der Geest email: samelinoa@gmail.com http://www.mathworks.nl/matlabcentral/fileexchange/authors/10584