I have written a code to

- Draw a spring
- Draw a point on the spring
- Animate the spring (up and down)
- Animate the point to move along with the spring

Now, the animation works till the point where the spring alone has to move. If I try to plot the point, the animation stops and the spring and the point appear stationary.

I have plotted the spring and the point together on the same subplot (of an axes handle in a GUI). How can I update the Zdata of both the plots in a loop?

`time = 0:pi/50:25*pi; % Time array`

radius = 2; % Radius of the coil spring

height = 10; % Height of the coil spring

x = sin(time) * radius; % Compute x and y

y = cos(time) * radius;z = height/(2*pi) * time; %Compute z which will be used later to animate

axis offha1 = subplot(1,2,1,handles.axes1);plot3(x,y,z,'Linewidth',2);set(ha1,'Position',[.016 .044 .142 .274]);hold onplot3(1.275, 1.545, 121.1, 'diamond',... 'LineWidth',1,... 'MarkerSize',10,... 'MarkerEdgeColor','b',... 'MarkerFaceColor', [0.7 0.7 0.7]); pause('on'); axis off ; while 1 t=0; axis off; for t= 0:1:1000 zaddf = sind(2.5*2*pi*t); znewf = z + zaddf; Zdataarray = {znewf , zaddf + 121.1} ; hChildren1 = get(handles.axes1,'Children'); axis off set(hChildren1,'ZData',Zdataarray); drawnow; pause(0.005); end end

When I run this code, the ZDataarray variable (concept suggested by this answer) becomes a cell with two elements – one a [1 X 1251] array and the other a single numerical value. I am not able to set the ZData of both the plots in a loop.

When I try with this code,

`set(hChildren1,'ZData',znewf);`

the spring animation works perfectly on its own, without the point on it.

How can I update both plots simultaneously, in a loop?

Thanks in advance.

## Best Answer