How to properly use nargin

I'm trying to use nargin to set a default input for a function, should that default not be previously defined by the user. I'm setting up the nargin loop in the same format my teacher used, however, I'm getting an error saying N is undefined, which is technically the point. Irronically I ran my teachers function and it also had the same error... so I'm a little stuck at the moment.

This is my function at the moment.

function y = estimate_pi_Leibniz_Clark_Brendan(N)
if (nargin == 0)
    N = 10;
end 
p = 0 ; 
for k = 0:N
  p = p + 4*((-1)^(k)*(1/(2*k+1)));
end
y=p;

[Jonas]

looks good, how did you run your function?

[Brendan Clark]

I just attempted to run in by entering

y = estimate_pi_Leibniz_Clark_Brendan(N)

into the command window, when I preset N the function works exactly how its supposed to, it only kicks back an error when I attempt to run it without predetermining N.

Answer 1

[the cyclist]

When you tried to call it like this:

y = estimate_pi_Leibniz_Clark_Brendan(N)

the problem is that in the calling workspace, the variable N does not exist, which is why you get that error. (The error is from the calling workspace, not from your function.)

Instead you could have called it as

y = estimate_pi_Leibniz_Clark_Brendan()

which would trigger your nargin statement.

[Brendan Clark]

I appreciate the explanation, knowing about why those weird errors populate really helps me moving forward.