function y = horner(x)
%HORNER - series expansion for exp(x) using Horner's rule
y = 1 + x.*(1 + x.*((1 + x.*((1 + ...
        x.*((1 + x.*((1 + x.*((1 + x.*((1 + ...
        x.*((1 + x./9)./8))./7))./6))./5))./4))./3))./2));
end

