[Insight-developers] add operator< and operator> support initk::Index

[Miller, James V (Research)]

For storage and searching lexicographically, I can understand the 
motivation.  But since it does not have a geometic meaning, I 
hesitate to put it into Index.  The whole purpose of Index to 
provide a link between a geometric space and the linear address
space an image uses to store its pixels.

Can we provide function objects (that people will have to go out
of their way to use) to provide a lexicographically ordering of 
Indices?





-----Original Message-----
From: Brad King [mailto:brad.king at kitware.com]
Sent: Friday, June 03, 2005 11:27 AM
To: Miller, James V (Research)
Cc: Gaetan Lehmann; insight-developers at itk.org
Subject: Re: [Insight-developers] add operator< and operator> support
initk::Index


Miller, James V (Research) wrote:
> What does it mean for an index to be "less than" another?
> 
> In your code snippet, you are defining to "less than" to be: if any component
> of the index1 is less than that component of index2, then index1 is less than
> index2.  Also, if any component of index1 is greater than that component in 
> index2, then index1 is greater than index2.

Actually it is defining a lexicographic total ordering.  It is not very 
useful geometrically but programatically it is useful for storage and 
searching.

-Brad