function testode

y0 = 1;
[T Y] = ode45(@frhs, [0 2], y0);
y = ftrue(T);

subplot(311);
plot(T,Y);
title('Approximate Solution');

subplot(312);
plot(T,y);
title('True Solution');

subplot(313);
plot(T, abs(Y-y));
title('Approximate Error');

end %function

%subfunctions
function f = frhs(t,y)
    f = t-y;
end %function

function f = ftrue(t)
    f = 2*exp(-t) + t - 1;
end %function