MATLAB: Creating a function to output factorials.

factorialfunction

Hi I am trying to create a user defined function that will allow me to enter an integer and it will output the given factorial.
function [y] = fact(x)
clc
y=1;
for i=1:x
y=y*i;
end
disp(y)
This is it and it is working but I also need it to display an error message if it is a negative integer or non integer (e.g 8.5) and for it to also display 1 for factorial 0.
I have tried adding if statements in the loop for if x<0 etc. but I am getting the same answer which is just 1.
It works for positive integers just not the others.
Any thoughts?

Best Answer

if ~isnumeric(x) || ~isscalar(x) || x ~= fix(x) %x == fix(x) checks for integer
error('Oh, oh, oh, oh, oh!')
end