RE: "particle" sliding along a curve

*To*: mathgroup at smc.vnet.net*Subject*: [mg70542] RE: [mg70516] "particle" sliding along a curve*From*: "David Park" <djmp at earthlink.net>*Date*: Thu, 19 Oct 2006 03:22:05 -0400 (EDT)

First define a single frame for the animation and then animate it. Needs["Graphics`Animation`"] frame[t_] := Plot[x^2, {x, -10, 10}, Epilog -> {AbsolutePointSize[6], Point[{t, t^2}]}, Frame -> True, Axes -> False, ImageSize -> 400]; Animate[frame[t], {t, -5, 5, 0.2}] SelectionMove[EvaluationNotebook[], All, GeneratedCell] FrontEndTokenExecute["OpenCloseGroup"]; Pause[0.5]; FrontEndExecute[{FrontEnd`SelectionAnimate[200, AnimationDisplayTime -> 0.1, AnimationDirection -> ForwardBackward]}] Usually when making an animation it is necessary to explicitly give the PlotRange so that all frames will have the same PlotRange. In this case the larger parabola gives the same PlotRange for all frames. When developing an animation you can also simply evaluate frame[0], or some specific time, to touch up the frame plot without doing the entire animation. David Park djmp at earthlink.net http://home.earthlink.net/~djmp/ From: Mattiephly at hotmail.com [mailto:Mattiephly at hotmail.com] To: mathgroup at smc.vnet.net Hi there. I'd like to create a Mathematica plot that displays a "particle" -- which will just be a small, black circle -- "sliding" along a curve. That is, when I execute the Plot command, I'd like to watch as the particle moves along the curve from one point to another. I've looked at the help documents for the built in Animation abilities, but I'm not sure how to make use of them. Do I really have to create a single plot for several positions of the particle, and then animate those consecutively? For example, I'd like my particle to slide along the parabola y = x^2, and I'd like the particle to "slide" from x = -5 to 5 (though maybe show the curve from x = -10 to 10). And I'd like to be able to control the "speed" of the particle, too. I appreciate any thoughts on this. Thanks a lot, R