Trace Marker Along Line

Hi

I have tried writing the code to trace marker along a line ( form matlab help)to make an animation

1. it doesn't work

2. I need to do it with polar function and not plot function

Can you help?

The code:

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

for k = 2:length(x)

      p.XData = x(k);

      p.YData = y(k);

      drawnow

end

[Walter Roberson]

Which MATLAB version are you using?

[Shani Gal]

Version 7.7.0.471 (R2008b)

[Walter Roberson]

The syntax you are looking at is R2014b or later only. You will need to switch back to the set() syntax

Answer 1

[KSSV]

clc; clear all ;
theta = 0:0.01:2*pi;
rho = sin(2*theta).*cos(2*theta);
% convert to Cartesian for marker tracing 
xx = rho.*cos(theta) ;
yy = rho.*sin(theta) ;
figure
polar(theta,rho,'r')
hold on
h = plot(xx(1),yy(1),'*b') ;
for i = 1:length(theta)
    set(h,'XData',xx(i),'YData',yy(i))
    pause(0.01)
end