Create a startpoint in form of a ring on my graph

Hi!

I wonder how to create a marker in form of a "ring/circle" on my startpoint a graph?

Thanks Cillian

Answer 1

[Thomas]

 try 

 a=[1 2 3 4];    %data to be plotted
  plot(a)
  hold on
  plot(a(1),'o','MarkerSize',10)    % start point with circle

[Cillian]

Yes, thanks. It seems to work.

But, just one more question, why is a(1)?

[Cillian]

Yes, thanks. It seems to work.

But, just one more question, why is a(1)?

[Thomas]

a(1) is the start point of your graph i..e the first value int he array a.

[Cillian]

Ah, of course. Okay, I get it now.

But what if I have this code:

tin=[0 5];

[TOUT,YOUT]=ode45(@myfun,tin,y0);

plot3(YOUT(:,1),YOUT(:,2),YOUT(:,3),'b')

I have tried to use your code into this above, but it won't work. How do I mark the startpoint here above?

[Thomas]

try the following

plot3(YOUT(:,1),YOUT(:,2),YOUT(:,3),'b') % your actual plot

hold on

plot3(YOUT(1,1),YOUT(1,2),YOUT(1,3),'o','MarkerSize',10) % start point

[Cillian]

Thanks again, it works great. :)