Help turning a permutation function into a script.

function [M, I] = permn(V, N)
narginchk(2,3);
if fix(N) ~= N || N < 0 || numel(N) ~= 1 ;
    error('permn:negativeN','Second argument should be a positive integer');
end
nV = numel(V) ;
if nargin==2, % PERMN(V,N) - return all permutations
    if nV==0 || N == 0,
        M = zeros(nV,N) ;
        I = zeros(nV,N) ;
    elseif N == 1,
        M = V(:) ;
        I = (1:nV).' ;
    else
        [Y{N:-1:1}] = ndgrid(1:nV) ;
        I = reshape(cat(N+1,Y{:}),[],N) ;
        M = V(I) ;
    end
end

This code takes two inputs and spits out a list of permutations. Example: permn(2:4,3) gives me this output;

     2     2     2
     2     2     3
     2     2     4
     2     3     2
     2     3     3
     2     3     4
     2     4     2
     2     4     3
     2     4     4
     3     2     2
     3     2     3
     3     2     4
     3     3     2
     3     3     3
     3     3     4
     3     4     2
     3     4     3
     3     4     4
     4     2     2
     4     2     3
     4     2     4
     4     3     2
     4     3     3
     4     3     4
     4     4     2
     4     4     3
     4     4     4

I would like to instead feed the V,N into the script as a variable, and store the output in a matrix.

Since narginchk can only be called in a function can i even do this?

Thanks!

Answer 1

[Andrei Bobrov]

M = V(fliplr(fullfact(ones(1,N)*numel(V))))