MATLAB: Unexpected output when trying to plot the solution to a system of nonlinear differential equations

nonlinear equations

The following Matlab code is meant to plot x(1) vs time and x(2) vs time separately, but only plots x(1) vs time. Despite there being two lines of code to generate each plot, one line is ignored. Does anyone have any suggestions as to how the code can be modified?
t = [0 10]; %time interval ranges from 0 to 10 s 
ic = [pi/3; 0; 0; 0]; % initial conditions = [θ θ' x x'] 
[t,x] = ode45(ode, t, ic);
plot(t,x(:,1), 'o') %the y axis represents 

plot( t,x(:,2),'o') %the y axis represents 
xlabel('x(m)');
ylabel('θ(rad)');
function dydx = fun(t,x)
%[x(1) x(2) x(3) x(4)] = [angle angular velocity x position x velocity] respectively 
    L = 0.5; g = 9.81;  
    dydx = zeros(4,1);
    dydx(1) = x(2);
    dydx(2) = (4*sin(x(1))*(5*L*cos(x(1))*x(2)^2 + 6*g))/(L*(20*cos(x(1))^2 - 23));
    dydx(3) = x(4);
    dydx(4) = -(5*sin(x(1))*(23*L*x(2)^2 + 24*g*cos(x(1))))/(6*(20*cos(x(1))^2 - 23));
end

Best Answer

Use
hold on
between the two plot commands.
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