% script err.m
% illustrate absolute and relative errors
% using sin(x) and an approximation x - x^3/6

% evaluate for x = 0 to x = 0.25 in steps of 0.05

for x = 0 : 0.05 : 0.25
   exact = sin(x);
   approx = x - x^3/6;
   abs_err = abs(exact - approx);
   if x == 0
      rel_err = 0.0;
   else
      rel_err = abs_err / abs(x);
   end
   fprintf('%8.2f%17.9e%17.9e%17.9e%17.9e\n', ...
      x, exact, approx, abs_err, rel_err);
end