Animate line but show marker only on current point

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I have data that overlaps itself a lot, so we're animating it for visualization purposes:
h = animatedline('Color', 'b');
DELAY = 0.001;
for i = 1:size(mapped_pts, 1)
addpoints(h, mapped_pts(i, 1), mapped_pts(i, 2));
drawnow
% pause(DELAY)
end
This works, but after a bit the "head" of the line gets harder to pick out, since it's small. I tried adding 'Marker', 'o' to the animatedline parameters, but that leaves a marker at every data point. I'd like to have a marker only on the most recently plotted point. Is this possible?

Accepted Answer

Steven Lord
Steven Lord on 16 Sep 2015
The COMET function does what you're looking for with respect to the marker, but it requires all the data to be specified when COMET is called. If that's okay for your application, that's what I'd use.

More Answers (1)

Brendan Hamm
Brendan Hamm on 16 Sep 2015
There is a function comet which does exactly this. It does not however allow you to control the pausing. Your other option is to create and delete a marker at every step:
f = figure;
ax = axes;
hold on
h = animatedline('Color', 'b');
DELAY = 0.001;
p = plot(ax,mapped_pts(1, 1),mapped_pts(1, 2),'o');
for i = 1:size(mapped_pts, 1)
p.XData = mapped_pts(i, 1);
p.YData = mapped_pts(i, 2);
addpoints(h, mapped_pts(i, 1), mapped_pts(i, 2));
drawnow
pause(DELAY)
end
  2 Comments
Ben
Ben on 16 Sep 2015
I can't change my "accepted answer", I guess, but I ended up going with this one so I don't have to muck around with changing a built-in function to control the speed. Thanks!
Brendan Hamm
Brendan Hamm on 17 Sep 2015
No Problem. I have used this method in the past to allow for more control.

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