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Re: Are points co-planar in (numDimensions-1)?

  • To: mathgroup at smc.vnet.net
  • Subject: [mg43289] Re: [mg43237] Are points co-planar in (numDimensions-1)?
  • From: Hugh Walker <hwalker at gvtc.com>
  • Date: Sat, 23 Aug 2003 08:09:22 -0400 (EDT)
  • Sender: owner-wri-mathgroup at wolfram.com

On Wednesday, August 20, 2003, at 09:26 PM, AngleWyrm wrote:

> Hi,
> I have a vector generator that produces sets of vectors in 
> numDimensions space. It has been said
> that they might be coplanar in numDimensions-1, and I wish to test 
> this.
>
> For instance, if the number of dimensions is set at three:
> dataSet=ReadList["data.txt", {Number, Number,Number}]
> Is dataSet coplaner in some 2D plane?

Here is one way:
Construct the numDimensions X numDimensions covariance matrix with the 
set of vectors and find its eigenvalues.One  zero eigenvalues will 
indicate the vectors lie in a space of dimension numDimensions-1: two 
zero eogenvectors will indicate the vectors lie in a space of dimension 
numDimensions-2; etc.

==========
Hugh Walker
Gnarly Oaks


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