Re: [boost] [pqs] [vectors]

From: David Abrahams (dave_at_[hidden])
Date: 2006-06-18 19:10:11

Janek Kozicki <janek_listy_at_[hidden]> writes:

> David Abrahams said:     (by the date of Sun, 18 Jun 2006 15:49:16 -0400)
>
>> Janek Kozicki <janek_listy_at_[hidden]> writes:
>> 
>> > That something IMHO is a wiki with specifications of those libraries
>> > (when decided to decouple dimensions, units and linear algebra (not
>> > geometry!)).
>> 
>> Since I'm working on a linear algebra library I've noting with some
>> confusion all the talk of vectors and matrices in the PQS thread.  Can
>> someone give me the three-sentence summary that explains why anyone
>> would think to couple linear algebra and units/dimensions in the first
>> place?  I mean, can't you just make a vector of velocities or
>> whatever?  Or is this about vectors where each element has different
>> dimensions?
>
> Yes, it is just about vectors and matrices where each element has
> different dimensions. It is useful for certain calculations. Leland
> Brown gave an example from his own program:
>
> http://lists.boost.org/Archives/boost/2006/06/106412.php
>
> My apologies for lack of imagination to get a good name. I picked
> 'linear algebra' just becasue I was sure that 'geometry' (suggested by
> Andy) is certainly a bad name. But now Geoffrey Irving has now a better
> idea to call it 'vectors'. Maybe even 'small vectors'.

I don't think that's an improvement, if you're working with matrices
too.  Sounds like linear algebra to me.

My library is designed to work with fixed- as well as variable-sized
structures, and it should be possible to use fusion to build
heterogeneous vectors and matrices compatible with my library, so I
hope no extra library will be needed.

-- 
Dave Abrahams
Boost Consulting
www.boost-consulting.com