Date: Feb 14, 2011 10:07 PM
Author: Gordon Sande
Subject: Re: Refresh My Mind About This: Similarity of Two Vectors of Data-Points

On 2011-02-14 22:34:04 -0400, Mike said:

> Hi,
> 
> Two single points (a and b) are identical (similar) if a-b=0
> 
> Assume you have two vectors of N data-points: V1(a1,b1,c1,...) and
> V2(a2,b2,c2,...). One would say V1 and V2 are dientical if V1-V2 = (a1-
> a2,b1-b2,c1-c2,...) = (0,0,0,...)
> 
> Now assume I have large # of such vectors Vn and want to see which
> ones are identical to which ones. Is there a way to convert each
> vector into a single value so I can see which vectors have same values
> (i.e., same elements)?
> 
> Thanks,
> Mike

If you want to find equal groups just (multiple key) sort and then look
for ties. Is there some other side condition you forgot to mention?