@Preben Alsholm Thanks, yes it was Maple 12.

However, I now have Maple 2015 on a different machine.  On that, the images of the traiangle look great, but the animation doesn't run -- or if it does, it finishes in a small fraction of a second.  I can't see anything.  There are no error  messages.

I will try your new code on my Maple12 machine.

Thanks!

@Preben Alsholm 

> animate(display, [('pointplot3d')(pts, symbol = solidsphere, symbolsize = 50), ('pointplot3d')(ptsL, connect, thickness = 3, color = black)], t = 0 .. 50, frames = 100);
%;
Error, (in plots/animate) expecting plot structure but received: plots:-pointplot3d([[0, 0, (1/4)*cos(0.)], [1+(1/5)*sin(0.), 1, 1], [-1, 0, (1/6)*sin(1.)]], symbol = solidsphere, symbolsize = 50)

Earlier, I see the little spheres at the vertices of the triangle only at two of the vertices.

I am having trouble understanding your code.

First, your random polys each contain x, y, dx, and dy.  That is far more than I need.  Perhaps it makes no difference, but as I wrote above, I have one equation containing only x, dx, and t, and a second containing only y, dy, and t.

Secondly, you wrote:

    deq1:=diff(eq1,t);
    deq2:=diff(eq2,t);

Why this?  Why differentiate the equations, making them more complicated??

Thirdly, when I ran your example as given, the final plot has two graphs. It seems to be that x and y have both been plotted as functions of t.  I don't want that.  The whole point is to get the graph of (x,y).  t should not appear on the plot in any way.  We don't care about t in the end.

Robert H. Lewis

Fordham University

I am having trouble understanding your code.

First, your random polys each contain x, y, dx, and dy.  That is far more than I need.  Perhaps it makes no difference, but as I wrote above, I have one equation containing only x, dx, and t, and a second containing only y, dy, and t.

Secondly, you wrote:

    deq1:=diff(eq1,t);
    deq2:=diff(eq2,t);

Why this?  Why differentiate the equations, making them more complicated??

Thirdly, when I ran your example as given, the final plot has two graphs. It seems to be that x and y have both been plotted as functions of t.  I don't want that.  The whole point is to get the graph of (x,y).  t should not appear on the plot in any way.  We don't care about t in the end.

Robert H. Lewis

Fordham University

Thank you.  I'm going to try your code.

Robert H. Lewis

Fordham University

Thank you.  I'm going to try your code.

Robert H. Lewis

Fordham University

The equations for x(t) and y(t) are similar.  Each is an approximately 230 term polynomial.

The polynomial for x(t) has degree 4 in x, degree 4 in dx/dt, and degree 36 in t. Similarly, the polynomial for y(t) has degree 4 in y, degre 4 in dy/dt, and degree 36 in t.  A reparametrization might decrease the degree in t.