MATLAB: Error in a function

circle area function

Good day.
I have the following function and I can't seem to be able to fix the error. This is a function that was in a pdf file I'm learning from and it told me to put it into matlab to see how it works and I'm pretty sure it was not supposed to do what it has done. This is NOT for an assignment or any other important thing that requires my own working, just so your concense is eased. You might it suspiciouse that I state this but I have been asked this question before so I answered it ahead of time.
Here is the function so you can copy it into your own Matlab.
function A = circle_area(diameter)
% help comments
% This function calculates the area of a
% circle. [Output units] = [Input units]^2
% Area = circle_area(diameter)
r = diameter/2;
A = pi*r.^2;
A = circle_area(0.2)

Best Answer

Have I named it correctly?