How to make two plots happen at the same time on two different axes?

Hello,

My problem is I have two graphs that draw things out at the same time, but they are on different axes. I want them to run in sync with each other so you can see at the same time. As of now one gets drawn out, then after that is done the other starts plotting its points.

Any help would be appreciated!

Thanks

[Adam Danz]

Why not put both plot updates in the same loop where each iteration updates the data on plot 1 and then updates the data on plot 2 and then uses drawnow() on each axis at the end of the iteration; then continue to the next iteration.

[William Fantin]

Hmmm, I was thinking this, but I guess I dont know how to specify that I want one on a certain plot and want the other on a different plot?

Lets say I have this code:

V=linspace(-5,5)

for k=V:length(V)
    y=sin(V)
    plot(y,'r')
    
    w=cos(V)
    plot(w,'b')
end

How would I go about plotting the w and y on different axes in a gui?

Thank you!

Edit: I just re-read your post and I do not know about updates.

[Walter Roberson]

Search for tag:always-parent in the search box

Answer 1

[Adam Danz]

Here's a demo to follow. It creates two axes that display the time course of a sine and cosine wave. Run it, step through it to understand what's going on, and I'd be glad to address any questions.

% Create data for both axes
x = -pi:.05:pi; 
y1 = sin(x);
y2 = cos(x);

% Set up figure(s)
% Note: A lot of this section would be more efficiently done by looping through 
% both axes instead of having duplicate commands.  
figure
s1 = subplot(2,1,1); 
s2 = subplot(2,1,2); 
ylabel(s1,'sin(x)')
ylabel(s2,'cos(x)')
xlim(s1,[min(x),max(x)]); 
xlim(s2,[min(x),max(x)]); 
ylim(s1,[min(y1),max(y1)]); 
ylim(s2,[min(y2),max(y2)]);
hold(s1,'on'); 
hold(s2,'on')
grid(s1,'on')
grid(s2,'on')

% Plot empty lines that will be updated within the loop
% Note: In this exmaple I could have used the real x values below but
% I wanted to show how you update them within the loop.  
p1 = plot(s1,nan(size(x)),nan(size(y1)),'-o'); 
p2 = plot(s2,nan(size(x)),nan(size(y2)),'-o'); 

% Update each iteration
for i = 1:length(x)
    % Update values
    p1.XData(i) = x(i); 
    p1.YData(i) = y1(i); 
    p2.XData(i) = x(i); 
    p2.YData(i) = y2(i); 
    % Update axes
    drawnow
end