plotting a function from an m file

I've set up this function representing a sum in an m. file:

function[fx]=f(x,N)

    n_fac=1;

    sum=1;
    for n=1:N
         n_fac=n_fac*n;
        sum=sum+(x^n)/n_fac
    end
    
    fx=sum
end

And I want to plot this function using the vector x = -2:0.5:5, but when I do the command plot(x,f(x,100) (where N = 100), then it gives me an error output, that says:

Not enough input arguments.

Error in f (line 7)
    for n=1:N

Error in appm2360homework3 (line 8)
plot(x,f(x))

How do I go about creating a plot from my m. file function?

Answer 1

[Rik]

You forgot to add 100 in your actual code:

plot(x,f(x,100))

You should avoid using sum as a variable name, because it shadows the internal function, which can lead to strange behavior. Also, you forgot to use the layout tools to make your code more readable and you forgot to write comments in your code.

[Georgia Hastie]

OK, I fixed those two things. I changed my sum variable to S and I included 100 in my code plot(f(x,100)), but now it's giving me this message:

Error using ^ (line 51)

Incorrect dimensions for raising a matrix to a power. Check

that the matrix is square and the power is a scalar. To

perform elementwise matrix powers, use '.^'.

Error in f (line 9)

S=S+(x^n)/n_fac

Error in appm2360homework3 (line 7)

plot(x,f(x,100))

[Rik]

Replace ^ and / by .^ and ./ to make sure you are using element wise operations instead of array operations.

And why did you remove the first x in your call to plot?