Hi Patiphol,
I believe you wish to plot this second order ode dependent on x. Please find a reference example
fx = linspace(0, 10, 50);
f = sin(2*fx);
xspan = [pi*0.25 pi*0.5];
y_0 = [3 0];
[x,y] = ode45(@(x, y) myode1(x, y, fx, f), xspan, y_0);
plot(x, y(:,1), '-r ', x, y(:,2), '--g');
legend('y(1)', 'y(2)');
xlabel('x');
ylabel('y Solution');
function dydx = myode1(x, y, fx, f)
f = interp1(fx, f, x);
dydx = [y(2); f - 4*y(1)];
end
Please refer to the following MATLAB Documentation page on the 'ode45' function and relevant information on the 'Differential Equation'.
