Re: [eigen] Re: Eigen 2, expression templates, and tvmet

[Andre Krause <post@xxxxxxxxxxxxxxxx>]

Benoît Jacob wrote:
> On Tuesday 29 May 2007 20:39:25 Schleimer, Ben wrote:
>> Hey Benoit,
>>   Tvmet looks very good. It's benchmark scores for small sizes is
>> amazing...
>>
>> I can only say that if eigen2 has a consistant wrappers for both the gmm++
>> and tvmet classes and copy constructors for both, it'll seriously rock...
> 
> So I should clarify that in my plan, eigen2 doesn't have a wrapper for tvmet; 
> instead, eigen2 _is_ a "fork" (or, if you prefer, a sequel) of tvmet.
> 
> The difficult part will be to rip the expression template mechanisms out of 
> tvmet in order to be able to reuse them for gmm++.
> 
>>> I wrote to the TVMET developer and to the -devel mailing list, but got no
>>> reply. The mailing list archives show only spam in the recent past, and
>>> the last release dates back to 2005-04-26. So I think it's safe to say
>>> that TVMET is unmaintained and orphaned.
>> Weird, so was TinyVector before it. Hopefully eigen2 will be better
>> maintained...
> 
> According to its website, tvmet was only used by 2 projects. Eigen1 is already 
> used by at least 5 projects.
> 
> So I start now with Eigen2.
> 
> -Benoit

hello benoit, i like the idea to stand on tvmets shoulders! i like
tvmet, we are using it internally for a small simulation project. but
tvmet is missing some stuff (for example pseudoinverse calculation),
that hopefully will then be available with Eigen2.

a wish:

could you keep the number of include files low? and please, no c++ files
if possible. what i most like about boost, tvmet and other template
libraries is, that one does not need to link with a library. binary
libraries are a bit portability issue. it never works the way i like.
somethimes, they cannot be linked statically, sometimes they depend on
other runtimelibraries to be in a specific format whatever.
if one cannot avoid to have a c file, then just a single one that can be
easily added to the project and directly compiled.

"single header, single c(++) file" library is a cool concept.

the way tinyxml is - it has just a few headers and also maybe 3 or 4 c++
files. all i do is add them to my visual studio project and i am done.


in the times of fast incremental linkers and precompiled headers there
is imho no more need for stupid library hassles. expect of course for
really HUGE libs. but not for the average small helper lib.

anyway - i am eager to see eigen2, it will definitely rock! tvmet was
very very well designed, i liked everything about it! eigen2 can only
get better!