animatedline plot with sliding window view

So I have an hour long plot that I want to look at as an animation in 2 second increments.

r = [ 0 2];
for step = 2
        for K = 1:length(t)
            xlim(r)
         addpoints(an,t(K),C14_theta(K));
         drawnow limitrate
        end
        pause on 
         pause(5)
        r = r + step;
        xlim(r)
end 

This is what I have currently. My issues that I need resolving are as follows:

• If I leave the r = r +step outside of my for loop then I can only see the first two seconds of my trace and the window doesn't pan.
• If i put both the pause and the r = r+ step in the for loop it pauses for 5 seconds every time it plots a data point as well.
• If I leave out the pause but put the r = r+ step in the main for loop the x axis changes so fast that I can't see any of my data points.

There are 40001 data points in a 2 second period, and it takes roughly 5 seconds to execute that. Please could somebody help so that my x scale is 0-2 for the first two seconds and during that time all of the data points in the first two seconds are plotted, and then I pan to x axis 2-4 and all of the points between 2 and 4 seconds are plotted.

Answer 1

[Nitin Kapgate]

You can refer to the following code snippet to solve the issue you are facing.

The code demonstrates a way to display data for every seconds (with a 2 second pause in the updation of the graph).

For future reference, the plots can be exported to individual frames (containing 2 second data plot) and subsequently to a GIF file as demonstrated in the code below.

close all;

% Create data for 10 seconds, 5 datas every 2 seconds.
data = 1:5:125; % 25 data points
time = 0.2:0.2:10;

% Generate the frames to be written to a GIF
for k = 1:5
    if(k==1) % Only create plot for the first iteration, update subsequently
        figure();
        hold('on'); grid('on');
        h = plot(time(1:5), data(1:5));
        pause(2); % Comment/Delete this line if no pause of 2 seconds is required
        legend('Animated graph, Updated every 2 Seconds');
        xlabel('Time (seconds)');
        ylabel('Data');
    else
        set(h, 'xdata',time(k+1:k+5));
        set(h, 'ydata',data(k+1:k+5));
        pause(2);  % Comment/Delete this line if no pause of 2 seconds is required
    end
     title(['k = ' num2str(k)]);
    % Save the frame as png with a resolution of 150 pixels per inch
    print(['Frame ' num2str(k)], '-dpng', '-r150');
end

% To generate the animated gif
GifName = 'AnimatedGraph.GIF';
delay = 2;    % Delay between frames (2 seconds)
for j = 1:5
    [A, ~] = imread(['Frame ' num2str(j) '.png']);
    [X, map] = rgb2ind(A, 256);
    if j == 1
        imwrite(X, map, GifName, 'gif', 'LoopCount', inf, 'DelayTime', delay)
    else
        imwrite(X, map, GifName, 'gif', 'WriteMode', 'append', 'DelayTime', delay)
    end
end

[Anna van der Stap]

Thank you very much! I actually already solved it for myself in the meantime by just creating an extra matrix with the corresponding limits of the axis so that I could index into it in the same way. As follows:

    Time1 = ;
    Time2 = ;
    point1 = find(t == Time1);
    point2 = find(t == Time2);
    figure
    an = animatedline('MaximumNumPoints',length(t)); 
    two_seconds = 40001;
    lims = 0:2:max(t);
    limits = repelem(lims,(two_seconds-1));
    ylim([-0.2000, 0.2000]
    v = VideoWriter('seizure.avi');
    open(v);

    for K =point1: 5 :point2
        addpoints(an,t(K),C14_theta(K));
        xlim([limits(K),(limits(K)+2)])
         drawnow limitrate nocallbacks
         frame = getframe(gcf);
         writeVideo(v, frame);
    end
    close(v)
       hold off
       
       
       

But thank you very much indeed for your suggestion!