Re: [ublas] How to solve systems of linear equations?

Subject: Re: [ublas] How to solve systems of linear equations?
From: Rui Maciel (rui.maciel_at_[hidden])
Date: 2010-03-11 13:25:14

Thomas Klimpel wrote:
> What has "boost::ublas" done to you that you compare it with TNT? 

I don't understand. What do you mean by that?

> (What I
> hate most about TNT is the choice between a really old stable version 1.26
> and an old beta version 3.0.12. If they would at least manage to release a
> stable 3.0 version.) 

Well, they did put up a decent documentation which also encompasses  a hand 
full of decomposition routines. 

> There are many libraries like "boost::ublas" out
> there:
> 
> glas

Not available through Ubuntu's repositories.

> MTL4

Not available through Ubuntu's repositories.

> eigen2

I was also considering eigen along with TNT.

> NT2 (I think Joel Falcou has worked on an overhauled version with a new
> name)

Not available through Ubuntu's repositories. 

> FLENS

Not available through Ubuntu's repositories. 

> 
> and many other (so add 
> blitz++

No support for sparse matrices.

> MTL2

Not available through Ubuntu's repositories.

> TNT

Erm...

> lapack++

From lapack++'s site:

"NOTE: This package is being superseded by the Template Numerical Toolkit 
(TNT)"

> ?, ?? and ??? to the
> list if you like).
> 
> I have evaluated some of these at some point in time, and may have more
> opinions about them than I want to share with you. However, I fail to see
> the merit of TNT over any of these, including "boost::ublas". 

I believe that it's important to not only have a decent documentation but also 
enjoy having basic features available.  If the available documentation doesn't 
quite cut it and if their users (or at least clueless newbies such as myself) 
must rely on obscure bindings which aren't documented nor readily available 
then the though of just picking up a better alternative surely must cross 
anyone's mind.

> There was a
> really "huge" table in an older version of the documentation for "glas"
> with many, many numerical libraries and some of the features they
> supported at that point in time. It was probably a wise decision to remove
> this table from the documentation, since it would have been an impossible
> task to keep it up to date.

This is straying a bit away from the subject but when faced with the choice of 
having a documentation that may not be quite up to date and not having one at 
all, I believe that no one would choose to not have any documentation.

Rui Maciel