Factorial Function Setting problem

Hi, I just set up my code for a factorial function, shown below:

function y = my_factorial(x);
if x == 0
    y = 1
else y = x * factorial(x-1);
end;

but Matlab keeps saying not enough input arguments. What's the problem of it?

Answer 1

[Stephen23]

There is nothing wrong with your function, it works fine:

>> my_factorial(3)
ans =  6

The problem is how you are calling it. Are you clicking the Run button on the toolbar ? MATLAB made a poor design decision by adding that button, because now lots of beginners click that button and are surprised when their code does not work... in fact they are just forgetting to call their function with its required input arguments. Chances are you forgot to supply the input argument.

[Kev W]

Cool stuff.Now the case is I would like to build a function for n!. What am I going to code to make it done?

[Stephen23]

 function y = myfun(x)
 y = prod(1:x);
 end

Answer 2

[Star Strider]

You have to call your function with an argument in your script or in the Command Window. You cannot click ‘Run’ in the Editor.

EDIT — The easiest way to create your own factorial function:

my_factorial = @(n) prod(1:n);

[Kev W]

The hint asked us to write a code like this:

function y = your_func_name(x);
y = x;
end;

how do we use a form like thi sto write a n! function? (Purely new hand :( )

[Star Strider]

I would do it this way:

function y = my_factorial(x);
if rem(x,1) ~= 0
    error('Argument ‘x’ must be an integer.')
end
y = prod(1:x);
end