[Date Index] [Thread Index] [Author Index]

Re: Re: Graphics Question

• To: mathgroup at smc.vnet.net
• Subject: [mg35469] Re: [mg35459] Re: Graphics Question
• From: jmt <jmt at agat.net>
• Date: Sun, 14 Jul 2002 06:19:42 -0400 (EDT)
• References: <agjj0o$24v$1@smc.vnet.net> <agm3v1$53i$1@smc.vnet.net> <200207130748.DAA08580@smc.vnet.net>
• Sender: owner-wri-mathgroup at wolfram.com

I would like to add :
Some interactivity can be achieved using java graphics capabilities, 
consequently should be OS independant.

On Saturday 13 July 2002 09:48, AES wrote:
> > > Is there any way to create interactive graphics?  It seems all
> > > animation is done by precalculating frames.  For some things this is
> > > ok, but it would be nice to be able to dynamically alter a graphic, and
> > > even better make changes based on input of various sorts.  Perhaps an
> > > add-on package exists?  Or perhaps in an upcoming version?
>
> I believe this is a fair and significant question to pose -- and
> unfortunately a difficult one for Mathematica to answer.
>
> What this poster would like, and so would I, is the ability to add a new
> point or object, or a succession of new objects, to an existing
> on-screen plot, without redrawing the whole plot -- for example, to see
> a curve "crawl" across a plot without calculating and storing a whole
> bunch of nearly identical images, or to let a user interactively move an
> object in a plot with the mouse and see other parts of the plot change
> appropriately in a fluid and instantaneous fashion.  We'd like this to
> be fast, and also very simple to program (an Mathematica command
> "ShowAdded[Graphics[--]]" that adds a new graphics element to a plot
> that's already on screen, along with an "Erase[Graphics]" command.)
>
> Unfortunately, as I understand it, Mathematica graphics just aren't set
> up to function in this fashion.  These capabilities can be simulated to
> some extent, if the computer is fast enough, but I believe the
> fundamental architecture of Mathematica is based  on formulating, then
> displaying one complete PostScript graphic at a time.  The idea of
> adding new points to an existing, already on screen plot, without
> redrawing the whole image, is not part of the underlying structure.
>
> I don't fault Mathematica for this; It may not be possible to do
> otherwise in a multi-platform package.  Adding to a display already on
> screen I believe implies having access to system-level or "screen-level"
> aspects of the computer, and these are greatly different from computer
> to computer.
>
> Comments from more knowledgeable people obviously welcomed . . .
>
> [Incidentally, is there an "Erase" command in Mathematica now?  Can I
> program
>
>     myGraphic =Graphics[bunch-of-graphics-stuff]
>
>     Show[myGraphic]
>
>     Erase[myGraphic, one-piece-of-this-stuff]
>
>     ReShow[myGraphic]
>
> ???]

• References:
  • Re: Graphics Question
    • From: AES <siegman@stanford.edu>