How to draw the direction field of van der pol oscillator?

Hi, I am trying to get the direction field and phase portrait shown on this wiki page:

https://en.wikipedia.org/wiki/Van_der_Pol_oscillator

My code:

options = odeset('MaxStep',0.5);
temp = inputdlg('Enter mu value');
mu = str2double(temp{1,1});

[t,y] = ode45(@(t,y) vdp1_1(t,y,mu),[0 10],[2; 0],options);

figure(1);
plot(t,y(:,1)), 
xlabel('time t');
ylabel('Y1(t)');
title('t vs Y1(t)');

figure(2);
plot(t,y(:,2))
xlabel('time t');
ylabel('Y2(t)');
title('t vs Y2(t)');

figure(3),
 plot(y(:,1),y(:,2)) , hold on
quiver(y(:,1), y(:,2), gradient(y(:,1)), gradient(y(:,2) ))
hold off

function dydt = vdp1_1(t,y,mu)

dydt = zeros(2,1);
dydt(1) = y(2);
dydt(2) = [mu * (1-y(1)^2)*y(2)-y(1)];

end

Output

Desired output: How to get the direction field on top of this as shown in the wiki page figure https://en.wikipedia.org/wiki/Van_der_Pol_oscillator#/media/File:VanDerPolOscillator.png

Thanks, Gopi

[KSSV]

Similiar question: https://in.mathworks.com/matlabcentral/answers/331445-how-can-i-draw-vector-direction-field-for-van-der-pol-oscillator

Answer 1

[KSSV]

You have to follow like shown in the link:

http://matlab.cheme.cmu.edu/2011/08/09/phase-portraits-of-a-system-of-odes/