ex26ch2.m

these codes are for solving OED with matlab

function ex26ch2
options = odeset('Stats', 'on', 'Events', @ex19ach1e);
tspan = [0 2];
yzero = [0 ; 0];
[t,y,te,ye,ie] = ode45(@ex26ch2f, tspan, yzero, options);
exactt = zeros(9,1);
for i = 1 : 9
    exactt(i) = 2 * sqrt(i/10);
end
disp('ie follows: '), disp(ie)
disp('ye follows: '), disp(ye)
disp('Approximate t follows: '), disp(te)
disp('Exact t follows: '), disp(exactt)
%===========================================================
function yprime = ex26ch2f(t,y)
yprime = [y(2) ; 1/2];
function [value, isterminal, direction] = ex19ach1e(t,y)
isterminal = [0;0;0;0;0;0;0;0;0];
direction = [0;0;0;0;0;0;0;0;0];
value = zeros(9,1);
for i = 1 : 9
    value(i) = y(1) - i / 10;
end