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Re: Vector operations,

  • To: mathgroup at smc.vnet.net
  • Subject: [mg70019] Re: [mg69993] Vector operations,
  • From: "Adriano Pascoletti" <pascolet at dimi.uniud.it>
  • Date: Sat, 30 Sep 2006 05:12:54 -0400 (EDT)

Something like this?

L = {{1/2, 1/2}, {1, 0}, {0, 1}, {0, 0}};
Transpose[RotationMatrix2D[t].Transpose[L]]

yields

{{Cos[t]/2 + Sin[t]/2, Cos[t]/2 - Sin[t]/2}, 
  {Cos[t], -Sin[t]}, {Sin[t], Cos[t]}, {0, 0}}


Adriano Pascoletti

mickey wrote ..
> 
> Hi,
> 
> I have a list of vectors such as
> 
> {{1/2, 1/2}, {1, 0}, {0, 1}, {0, 0}}
> 
> I want to rotate them all by the same angle. Right now, what I do is 
> multiply each by RotationMatrix2D[t] and iterate over the list. Is there
> a more efficient way to do this?
> 
> Thanks,
> -M
> 


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