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Re: Normal with GeometricTransformation

  • To: mathgroup at smc.vnet.net
  • Subject: [mg110414] Re: Normal with GeometricTransformation
  • From: Peter Breitfeld <phbrf at t-online.de>
  • Date: Thu, 17 Jun 2010 02:03:26 -0400 (EDT)
  • References: <hva5vq$qcf$1@smc.vnet.net>

That's strange, but you could use a TranformationFunktion to get the
explicit coordinates:

tf=TranslationTransform[{0.5, 0.5}]
tf/@gr
Out= Line[{{0.5, 0.5}, {1.5, 0.5}, {1.5, 1.5}, {0.5, 1.5}, {0.5, 0.5}}]

//Peter

"David Park" wrote:

> The "More Information" for the GeometricTransformation function states: 
>
>  
>
> "Normal[expr] if possible replaces all GeometricTransformation[Subscript[g,
> i],\[Ellipsis]] constructs by versions of the Subscript[g, i] in which the
> coordinates have explicitly been transformed."
>
>  
>
> I just wonder if "if possible" means "never" because here is about as simple
> a case as one can get.
>
>  
>
> gr = Line[{{0, 0}, {1, 0}, {1, 1}, {0, 1}, {0, 0}}]; 
>
>  
>
> Graphics[{gr, Red, 
>
>   GeometricTransformation[gr, TranslationTransform[{.5, .5}]]}, 
>
>  Frame -> True] 
>
>  
>
> Now try to make the translation explicit by using Normal.
>
>  
>
> GeometricTransformation[gr, TranslationTransform[{.5, .5}]] // Normal 
>
>  
>
> It does nothing. There are cases where it would be useful to have the actual
> transformed points. Any ideas on how to make this work?
>
>  
>
>  
>
> David Park
>
> djmpark at comcast.net
>
>  <http://home.comcast.net/~djmpark> http://home.comcast.net/~djmpark/  
>

-- 
_________________________________________________________________
Peter Breitfeld, Bad Saulgau, Germany -- http://www.pBreitfeld.de


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