Mark, you're almost there. Here's how to "just get it running":
methods
function q = calculateSin(this, x)
q = sin(x);
end
end
Note that I've added an argument to your function. The first argument of all functions of a class will be the instance of that class being called. So when you call:
>> p = ParticleInBox();
>> p.calculateSin(2.0)
The second line is actually equivalent to:
calculateSin(p,2.0)
One way to think of what happens is that MATLAB basically checks the first argument of every call to a function. If that first argument is an object (as in your case, the object is p), and that object is of a class that has a method equivalent to the function being called (in your case the object p is of the class ParticleInBox, which has a method called calculateSin), then MATLAB will call that method, giving the object itself (ie, p) as the first argument.
So to answer your question, your original function signature had only one argument, which is by default the object (even though you used the variable name x). When you called the function with a second argument 2.0 you gave it more arguments than it expected.
