function M=multinom(N, n) 
% multinom(N, n)  multinomial coefficient 
% 
%    n is a row vector [n1, n2, n2....] where n1+n2+....=N 
% 
%    for a matrix n, each row in n must sum to its corresponding value in  
%    the row vector N - fill empty spaces with zeros 
if min(sum(n')==N)==0 
   error('n1+n2+... is not equal to N') 
end 
M=fact(N); 
F=prod(fact(n')); 
M=M./F;