Trace Marker Along Line

This example shows how to trace a marker along a line by updating the data properties of the marker.

Plot a sine wave and a red marker at the beginning of the line. Set the axis limits mode to manual to avoid recalculating the limits throughout the animation loop.

x = linspace(0,10,1000);
y = sin(x);
plot(x,y)
hold on
p = plot(x(1),y(1),'o','MarkerFaceColor','red');
hold off
axis manual

Move the marker along the line by updating the XData and YData properties in a loop. Use a drawnow or drawnow limitrate command to display the updates on the screen. drawnow limitrate is fastest, but it might not draw every frame on the screen. Use dot notation to set properties.

for k = 2:length(x)
    p.XData = x(k);
    p.YData = y(k);
    drawnow
end

The animation shows the marker moving along the line.