clear all
clc
format long

b=1;
a=0;
n=64;
h=(b-a)/n;

f=@(x) exp(-x);

%{
odd=0;
even=0;

for i=1:n
  if mod(i,2)=1
    odd=odd+f(a+i*h);
  end
end

for j=1:n-1
  if mod(j,2)=0
    even=even+f(a+j*h);
  end
end

CompSimpson=(f(a)+4*odd+2*even+f(b))*h/3


%}

SimpleSimpson=0;
for l=0:n/2-1
  k=2*l+1;
  SimpleSimpson=SimpleSimpson+(f(a+(k-1)*h)+4*f(a+k*h)+f(a+(k+1)*h))*h/3;
end;
SimpleSimpson
Exact=1-exp(-1)