Generic_Roots

Generic_Roots

[John B. Matthews]

Although they never became standard, I've written implementations of

AI-356: Ada.Numerics.Generic_Real_Arrays.Generic_Roots
AI-356: Ada.Numerics.Generic_Complex_Arrays.Generic_Roots

The updated numerics packages and some test code are available here

<http://home.roadrunner.com/~jbmatthews/misc/groots.html>

The implementation uses the Durand-Kerner-Weierstrass method:

<http://en.wikipedia.org/wiki/Durand-Kerner_method>

I'd be grateful for any comments you might have.

-- 
John B. Matthews
trashgod at gmail dot com
http://home.roadrunner.com/~jbmatthews/

Re: Generic_Roots

[Randy Brukardt]

Umm, AI95-0356 is "Support for Preemption Level Locking Policy".

You mean AI95-0346 "Roots of polynomials".

You might want to pass this implementation past John Barnes, as he was the 
original proposer of that AI.

                           Randy.

"John B. Matthews" <nospam@nospam.invalid> wrote in message 
news:nospam-5E13A8.13471601112008@news.motzarella.org...
> Although they never became standard, I've written implementations of
>
> AI-356: Ada.Numerics.Generic_Real_Arrays.Generic_Roots
> AI-356: Ada.Numerics.Generic_Complex_Arrays.Generic_Roots
>
> The updated numerics packages and some test code are available here
>
> <http://home.roadrunner.com/~jbmatthews/misc/groots.html>
>
> The implementation uses the Durand-Kerner-Weierstrass method:
>
> <http://en.wikipedia.org/wiki/Durand-Kerner_method>
>
> I'd be grateful for any comments you might have.
>
> -- 
> John B. Matthews
> trashgod at gmail dot com
> http://home.roadrunner.com/~jbmatthews/ 

Re: Generic_Roots

[John B. Matthews]

In article <gf0562$pr2$1@jacob-sparre.dk>,
 "Randy Brukardt" <randy@rrsoftware.com> wrote:

> "John B. Matthews" <nospam@nospam.invalid> wrote 
[...]
> > <http://home.roadrunner.com/~jbmatthews/misc/groots.html>
[...]

> Umm, AI95-0356 is "Support for Preemption Level Locking Policy".
> 
> You mean AI95-0346 "Roots of polynomials".

Yes, thank you! I've corrected the reference and added links to the CVS.

> You might want to pass this implementation past John Barnes, as he was the 
> original proposer of that AI.

Ah, I see now that he was the initial author. In the implementation 
advice, he suggested "using established techniques such as Laguerre's 
method." My implementation is definitely experimental, but it's a 
convenient alternative. My test cases are limited, so I'd be interested 
to hear of any anomalies. Of course, I expect most users are using BLAS.

-- 
John B. Matthews
trashgod at gmail dot com
http://home.roadrunner.com/~jbmatthews/

Generic_Roots

[John B. Matthews]

Inspired by <http://sourceforge.net/projects/gnat-math-extn/> and as 
suggested by a correspondent, I've updated my experimental 
implementations of these two generic procedures:

AI95-0346: Ada.Numerics.Generic_Real_Arrays.Generic_Roots
AI95-0346: Ada.Numerics.Generic_Complex_Arrays.Generic_Roots 

<http://home.roadrunner.com/~jbmatthews/misc/groots.html>

The implementation is unchanged, but I've fixed a few style warnings and 
obviated the need to update the run-time library. I've tested it with 
GNAT 4.3.4 (Mac OS X 10.5) and GNAT 4.4 (Ubuntu 10.04). I'd welcome any 
reports of anomalies or regressions.

-- 
John B. Matthews
trashgod at gmail dot com
<http://sites.google.com/site/drjohnbmatthews>