Re: [boost] [rfc] A light weight statically typed matrix template class (again?)

From: Martin Bonner (Martin.Bonner_at_[hidden])
Date: 2007-12-11 07:37:18

From: Andreas Harnack
> Dave Steffen schrieb:
>> On Thursday 06 December 2007, Andreas Harnack wrote:
>>> Hi @,
>>> 
>>> shouldn't there be at least an elementary matrix class available
>>> in the standard? I notice there have been some discussions in
>>> the past, but there doesn't seem to be anything in the pipeline.
>>> So, is there any interest in a (really!) light weight statically
>>> typed matrix template class?
>> 
>>   No, there shouldn't be. :-)
> 
> Well, I'm looking forward to a passionate discussion ;-)
I think Dave's right.

>>   The C++ landscape is littered with such things, from simpler than
>>   your example to fantastically elaborate.  See
>>   <http://www.oonumerics.org/oon/> for a sample.
> 
> I'd take that as a proof that there is a need for
> standardization, however the result might look like.

That's a curious conclusion.  If there are lots of attempts, it suggests that it is really difficult to get people to agree on the preferred approach.
> 
> 
>>   One of the big problems is that everyone wants something slightly 
>> different.  Example: 

and this is the key point.

> Here, I think, we have a huge misunderstanding. I never tried,
> don't pretend I could and don't even want to provide a solution
> that suits anybodies need. 

Can I be excused a smile at this point?  I think you probably meant to say "I don't want to provide a solution that suits EVERYbodies needs". (Sie schrieben, ungefähr, "Mein Idee ist für niemand" nicht "Mein Idee ist nicht für jemand".)

> I think that's  impossible. I totally
> agree that there are plenty of good libraries out there, some of
> them even excellent. But I refuse to believe, that the C++
> community consists only of people who do high performance
> scientific computing. 
Certainly true.
> For them is reasonably well cared for. But what about the rest of us?

The trouble is that even if you ignore the HPC community, "the rest of us" are a pretty disparate bunch and there are lots of separate problems each of which can be described as needing a simple matrix class - but in fact each of them needing a /different/ simple matrix class.  

>>   An an example of a library that probably does exactly what you
>>   want, but way way fast, look at 'tvmet'.
> 
> Agreed, it does what I want. In fact, any library I looked and
> does what I want because all I want is really simple stuff. I
> just don't like to pay the price (i.e. the dependencies it
> introduces, the complexity that gets involved, the compile time
> overhead etc.).

Well, I don't see how adding it to boost is going to help then.  You'll get all that stuff (just boost rather than tvmet).

>>   My point is, I guess, that general-purpose one-size-fits-all
>>   libraries have historically been hard to use and slow; libraries
>>   that are easy to use and fast are not applicable to all uses.  
... and this is why matrices don't belong in the standard.

>>   I
>>   personally think this issue is rather fundamental to the "computer
>>   linear algebra" problem, and nobody has yet come up with The Good
>>   Solution (not for lack of work).
> 
> I totally agree, but as I said, that wasn't my intention. And by
> the way, talking about matrices does by no means imply to talk
> about linear algebra. It just happens that linear algebra
> peoples are the ones that talk most about matrices. :-)

But Dave's point

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Martin Bonner
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