How can I add animation on the existing subplots?

Hello,

I am trying to combine 5 graphs and a video and add a moving xline on each graph like a play bar. I was able to put graphs and video together, but I am struggling with adding the animation of moving xline on existing subplots. Also, it would be perfect if I could match the frame rate to play the video. The data were sampled at 2000 Hz whereas the video was recorded at approximately 30 Hz. I have attached my code and screenshot of the figure below just in case it helps.

I really appreciate any help.

for i = 2:6
    if i == 2
        s1 = subplot(5,7,[1,2]);
        plot(s1,t,data.data(:,i));
        xlim([0, t(end-1)])
        title('Vertical Ground Reaction Force')
        ylabel('N')
        xlabel('Time (s)')
    elseif i == 3
        s2 = subplot(5,7,[8,9]);
        plot(s2,t,movmean(data.data(:,i),100));
        hold on;
        area(t,max(movmean(data.data(:,i),100),threshold(i-2)),threshold(i-2));
        xlim([0, t(end-1)])
        title(data.labels(i,:))
        xlabel('Time (s)')
        ylabel('mV')
    elseif i == 4
        s3 = subplot(5,7,[15,16]);
        plot(s3,t,movmean(data.data(:,i),100));
        hold on;
        area(t,max(movmean(data.data(:,i),100),threshold(i-2)),threshold(i-2));
        xlim([0, t(end-1)])
        title(data.labels(i,:))
        xlabel('Time (s)')
        ylabel('mV')
    elseif i == 5
        s4 = subplot(5,7,[22,23]);
        plot(s4,t,movmean(data.data(:,i),100));
        hold on;
        area(t,max(movmean(data.data(:,i),100),threshold(i-2)),threshold(i-2));
        xlim([0, t(end-1)])
        title(data.labels(i,:))
        xlabel('Time (s)')
        ylabel('mV')
    else
        s5 = subplot(5,7,[29,30]);
        plot(s5,t,movmean(data.data(:,i),100));
        hold on;
        area(t,max(movmean(data.data(:,i),100),threshold(i-2)),threshold(i-2));
        xlim([0, t(end-1)])
        title(data.labels(i,:))
        xlabel('Time (s)')
        ylabel('mV')
    end    
end

%%
ax1 = subplot(5,7,[3:7,10:14,17:21,24:28,31:35]); % For video
filename = fullfile(path,file);
v = VideoReader(filename);
nFrames = v.Duration*v.FrameRate; % Number of frames
% Display the first frame in the top subplot
vidFrame = readFrame(v);
image(vidFrame, 'Parent', ax1);
ax1.Visible = 'off';
i = 1;
%% Animate
while hasFrame(v)
    pause(1/v.FrameRate);
    
    vidFrame = readFrame(v);
    image(vidFrame, 'Parent', ax1);
    ax1.Visible = 'off';
    s1 = xline(t(i));
    i = i + 1;
    
end

Answer 1

[dpb]

I've got more going on at the moment than have time to deal with the synchronization issue, but the animated line in an existing axes is simple -- just use

s1 = subplot(5,7,[1,2]);
...
hAL(1)=animatedline(s1);
...

will return the handle of an animatedline object in the given axes. You then can add data to the object with addpoints in a loop either in batches or one-by-one.

[Youngmin]

Thank you for answering my question. However, I am not sure where

hAL(1)=animatedline(s1);

should be. Does this line need to be right after each subplot? Also, does animatedline allow me to have a moving xline not just drawing my data?

[dpb]

Yes, create the object after the axes so you have the axes handle with which to associate each animated line -- the first call would be outside the time loop; the addpoints call inside when have new data.

You could have two animated lines in each, but neither animatedline nor xline is really designed for the purpose; for it I would suggest using xline but also similarly as with the animatedline, create one for each subplot axis at the same time as the animatedline, but then when updating, use the .Value property instead of calling xline again -- when you do that, you create a new line, you don't update the existing one...

hAx(1) = subplot(5,7,[1,2]);
hAL(1)=animatedline(hAx(1));
hXL(1)=xline(hAx(1),0);
...
% begin loop here after all axes/line objects are created...
while haveDataComing
  for ix=1:numel(hAx)       % use handle array so can iterate instead of duplicate
    addpoints(hAL(i),XnextDataAxis(i),YnextDataAxis(i));    % update new data each axes
    hXL(i).Value=XnextDataAxis(i);                          % and move the vertical line
  end
  haveDataComing=NewDataArrivedFlag;
end

The logic to determine how long to run may be from external event or if this is replaying previously recorded/computed data, then just a for...end loop over that array size may be substituted for a whle construct.