Re: Motion
- To: mathgroup at smc.vnet.net
- Subject: [mg78401] Re: Motion
- From: "Steve Luttrell" <steve at _removemefirst_luttrell.org.uk>
- Date: Sat, 30 Jun 2007 06:09:48 -0400 (EDT)
- References: <f62l97$cek$1@smc.vnet.net>
One of the very useful things about Manipulate is that it automatically
invokes Dynamic where it is needed.
The code fragment below does the sort of thing that you want:
Manipulate[If[r>0.49,r=0,r+=0.01];Graphics[Circle[u,r],PlotRange->{{-1,1},{-1,1}}],{{u,{0,0},"u"},Locator},{{r,0.25,"r"},0,0.5}]
You can move the centre of the expanding bubble by clicking and dragging the
locator.
Steve Luttrell
West Malvern, UK
"Tim Brophy" <timbrophy at mac.com> wrote in message
news:f62l97$cek$1 at smc.vnet.net...
> Hi everybody,
>
> I am trying to draw circles that will stay centered on a Locator and
> increase in size. I thought that this code might work. What am I
> doing wrong?
>
> DynamicModule[{p = {0, 0}},
> LocatorPane[Dynamic[p],
> Dynamic[
> Animate[
> Graphics[Circle[p, t], PlotRange -> {{-7, 7}, {-7, 7}}], {t, 0,
> 6}]]]]
>
> Tim Brophy
>