Animating a matlab calculated data over a given data in real time.

Hi,

I have simulated data of two different parameters y1 and y2 against variable x which I have plotted in Matlab using subplot function.

Now, I am calculating y1 and y2 using some other technique in Matlab for all x points using loop and I want that as soon as y1 and y2 are calculated for a given x, it should get updated in their respective subplots.

How to do that in Mtalab?

I know "drawnow" and "animatedline" command in Matlab but unable to fix my problem.

Answer 1

[Gyan Vaibhav]

Hi Manikant,

For your query, you will need to initialize an animateline object for each subplot and keep adding points to each object using the addpoints method. To update these on to the figure you can use the drawnow.

Here is a sample code:

x = linspace(0, 10, 100);
figure;

% Create two subplots
subplot(2,1,1);
xlabel('x');
ylabel('y1');
hLine1 = animatedline;
axis([min(x)-1 max(x)+1 -1 1])

subplot(2,1,2);
xlabel('x');
ylabel('y2');
hLine2 = animatedline;
axis([min(x)-1 max(x)+1 -1 1])


for i = 1:length(x)
    y1(i) = sin(x(i));
    y2(i) = cos(x(i));
    
    % Add points to animated lines
    addpoints(hLine1, x(i), y1(i));
    addpoints(hLine2, x(i), y2(i));
    
    % Update the plots
    drawnow %limitrate
    
    % Optional: 
    %pause(0.1);
end

Few quick tips:

1. You can set the limits for your x and y values, so as the animation looks nice.
2. You can use the pause function or "limitrate" with the drawnow function, so as the plot updates slowly.

Follow this link to know more: https://www.mathworks.com/help/matlab/creating_plots/line-animation-of-streaming-data.html

Hope this helps.

Thanks

Gyan

[manikant sinha]

Thanks Gyan for you kind help.

Meanwhile, I also tried this code and it fits my purpose.

clc;

clear;

close all;

x = linspace(0,4*pi,1000);

subplot(2,1,1)

y1 = cos(x);

plot(x,y1);

h1 = animatedline;

subplot(2,1,2)

y2 = sin(x);

plot(x,y2);

h2 = animatedline;

y3 = zeros(1000,1);

y4 = zeros(1000,1);

for k = 1:length(x)

y3(k) = cos(x(k));

addpoints(h1,x(k),y3(k));

drawnow

y4(k) = sin(x(k));

addpoints(h2,x(k),y4(k));

drawnow

end

%