Question: Dynamic viewpoint for animations

Hi,

I'm trying to modify the size of the window where an animation is shown. Tipically, this window has axis going from xmin to xmax and ymin to ymax but this causes some scaling problems when xmax-xmin>>ymax-ymin. I would like to focus in a certain region of my animation and change this viewpoint depending on the position of the elements of the animation. Can anybody help me?

This is my code:

> tf := 5;
> nfr := 201;
> pl := NULL;
> for i to nfr do

 dsv := dsn(tf*(i-1)*RealDomain[`^`](nfr-1, -1)); 

thv, xv, xcv, yv := seq(rhs(dsv[j]), j = [2, 4, 6, 7]); 

pl := pl, [CURVES([[xv, yv], [xv+R*cos(thv), yv+R*sin(thv)]], COLOR(RGB, 1, 0, 0)), circle([xv, yv], R, color = blue), circle([xcv, f(xcv)], 0.4e-1, color = black)] 

end do;

> p1 := PLOT(ANIMATE(pl));
> p2 := plot(prof, x = 0 .. 20);
> display({p1, p2});

Thanks