is it possible to add a 3D sphere marker to a 2D plot?

is there an easy way to do this? would it be possible to use the sphere command? its part of a movie so don't know how feasible using the sphere command would be.

[dpb]

sphere will create a 3D axis; you would have to somehow overlay it on the 2D one which would mean orienting it to only show the xy plane which reduces the appearance of the sphere to a circle since it's a projection onto the surface....

[Adam]

The fact you have a 2D plot is largely irrelevant to plotting a sphere apart from the issue of getting it in the right place, it being visible and as dpb says, if it is only viewed in 2d then it is just a circle anyway.

You can plot anything you want together on a set of axes though if you use hold on to avoid replacing the other things on the axes.

When you plot an image it is still on a 3d axes, just with an X-Y projection. If you click the rotate icon on the toolbar you will soon end up with a 3d view where your image is just a plane through it.

Answer 1

[Star Strider]

Try this:

[Xs,Ys,Zs] = sphere;

figure
for k1 = 1:0.03:3.2
    Xp = Xs + cos(k1*2*pi);
    Yp = Ys + sin(k1*2*pi);
    surf(Xp, Yp, Zs)
    axis([-3  3    -3  3    -3  3])
%     axis equal
    view(0,90)
    grid on
    refreshdata
    drawnow update
end
hold off

Experiment to get the result you want.