prob4plot.m

set(0, 'defaultAxesFontSize', 16)
set(0,'defaultTextFontSize',14)
set(0,'defaultLineLineWidth',3)
cd = 0.25;
m = 60;
g = 9.81;
dt = 0.1;
t = [0:dt:12]';
x = zeros(length(t),2);
x(1,:) = [1000, 0];
for i = 2:length(t)
    dx = prob4_ode(t,x(i-1,:));
    x(i,:) = x(i-1,:)+dt*dx;
end
c = figure(3);
x_heun = prob4ptC (@(t,x) prob4_ode(t,x), 0.1, [1000, 0], [0 12]);
plot(t, m/cd*log(cosh(sqrt((g*cd)/m)*t))+1000,t,x(:,1),t,x_heun(:,1)); 
legend('Analytical','Euler','Heuns','Location','Northeast')
xlabel('Time')
ylabel('Position')