Why doessn't my code work for compsite simpson one third rule?

this is the function file I created to integrate my function func=1+exp(-x) but my m file does not run?

function I=csimp(func,a,b,n)
h = (b-a)/(n-1);
xi0 = feval(func,a)+feval(func,b);
xi1 = 0; xi2 = 0;
for i = 1:n-1
  x = a+i*h;
  if mod(i,2) == 0
      xi2 = xi2+feval(func,x);
  else
      xi1 = xi1+feval(func,x);
  end
end
I= h*(xi0+2*xi2+4*xi1)/3;

this is my m file

a=0;
b=4;
n=7;
func=1+exp(-x);
I=csimp(func,a,b,n)

[Andrew Newell]

The formatting of your function was a bit weird, so I cleaned it up.

Answer 1

[Andrew Newell]

You weren't defining the function properly. Try this:

func=@(x) 1+exp(-x);

See Anonymous functions for how to define and use an inline function.