3.1 status report

[Dmitri A. Sergatskov]

On Wed, Jul 16, 2008 at 5:04 PM, David Bateman <adb014 at gmail.com> wrote:
> Jaroslav Hajek wrote:
>
>> I see, however, a couple drawbacks:
>> 1. most of GSL uses hard-coded double as the real type. Now that we
>> have true single precision, this is really a big drawback. I don't
>> reckon there are plans to change this state in GSL. And I can't see
>> any good way out of this.
>> 2. the "core" linear algebra operation of the MINPACK algorithms
>> (trust-region Levenberg-Marquardt and Powell's hybrid method) is the
>> QRP factorization. GSL has its own QRP code (as well as other linear
>> algebra codes) and employs it here. I think, however, that LAPACK is
>> fairly better.
>
> To me these are both good reasons not to use GSL. What I thought we were
> gaining with GSL was
>
> * upto date and maintained code
> * code that generally performed better
> * code that returned valid results for a wider range of input values.
>
> Though given the two points above I'm not sure GSL is worth it.
>

I guess one option is to lift the relevant code from GSL and adapt
it for octave data type and lapack. I think it is still better than carry
along the old Fortran code.

> D.
>

Dmitri.
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