[Help-gsl] Linear least squares, webpages and the next release

[Patrick Alken]

Hi all,

  There is significant new capability in GSL now for regularized linear 
least squares problems. I've added routines to do L-curve analysis as 
well as handle non-square Tikhonov regularization matrices. For those of 
you who have large least squares problems (ie: millions of rows in your 
matrix) stay tuned, as I'm working on adding some functionality for such 
problems.

  I've updated the GSL webpages on gnu.org to the latest in the git 
repository, since many new features have been added since the last 1.16 
release. The main page also now recommends to install GSL from the git, 
since 1.16 is quite outdated. This brings me again to the discussion of 
the next release of GSL.

  The last discussion of GSL v2.0 was in June 2014 (time goes too 
quickly!). I would like to reopen this discussion. The main points back 
then holding up v2.0 were:

1. New memory management (redesign of all GSL containers)
2. Incorporating LAPACK/LAPACKE/libflame

As far as I know, nothing has been done on either of these points, 
however a great deal of new functionality has been added to GSL in the 
meantime (sparse matrices, regularized least squares, running 
statistics, 2D interpolation, monotonic interpolation, new nonlinear 
least squares solver). I think (as I stated last year) that points 1 and 
2 should be postponed for GSL v3.0, and we should release v2.0 soon. At 
this point I am willing to make an executive decision and just do it :-) 
but I would like to check in with everyone first.

Over the past 2 years or so, looking at the git logs, I've been (mainly) 
the only person adding code to GSL. So I'd like to ask some poll 
questions (and recruit talented people to work on things) and so I'm 
posting to help-gsl as well. Here are some questions:

1. Is anyone out there using GSL besides me? :-)

2. What functionality would you like to see added to GSL?

3. Are you willing to develop and contribute the features you want?

4. Would you like to see a quick release of GSL v2.0, or are you content 
to work off the git repository?

Thanks,
Patrick