combination command

hi,

is there command compute combination ,for example comp. 4 of 20

thanks

Answer 1

[Jan]

What is the expected output? The number of combinations or a matrix of combinations itself? Do you want repetitions or not?

For some of these questions nchoosek is the needed function. For the others you find several tools in the FEX.

[huda nawaf]

thanks ,

nchoosek what I need , but need to see the cominations

ex. comb. 2 of 3

abc

ab,cb,ac

also, I need permutation command