[math] Incorporating JAMA code to solve problems?

[Chris Nix <ch...@gmail.com>]

All,

I've been working on another implementation of SVD as in issue
MATH-355<https://issues.apache.org/jira/browse/MATH-355>,
I'm mostly there.  However, I'm consistently impressed with the JAMA code.
 I email to ask a question that is perhaps quite bold for one such as me, so
new to Commons Math.

I'm using both the existing SVD implementations in CM and in JAMA as
benchmarks.  However, JAMA code is hard to beat, it's fast and stable.
 Additionally, current issues such as
MATH-383<https://issues.apache.org/jira/browse/MATH-383>,
MATH-465 <https://issues.apache.org/jira/browse/MATH-465> an
MATH-583<https://issues.apache.org/jira/browse/MATH-583> are
not suffered by JAMA.  JAMA is not only faster and more accurate for SVD,
but also for QR-decomposition.  There may be other examples where JAMA is
good, I'm yet to look.

CM is a great package, but I email to inquire if could we could solve easily
the issues above by simply implementing public-domain JAMA-like code within
the linear algebra sub-package or, perhaps more controversially, have JAMA
as a dependency to CM?

Is 'home-grown' code over public-domain code an objective of Commons Math?
 Like I say, it's a bold question.

Anticipating,

Chris

Re: [math] Incorporating JAMA code to solve problems?

[Phil Steitz <ph...@gmail.com>]

On 7/5/11 2:07 PM, Ted Dunning wrote:
> JAMA definitely is good algorithm wise.  API wise, it is very tied to a
> single representation which isn't acceptable.
>
> If you are finding JAMA more stable, then I would be +1 (in my own
> non-binding way) for copying the algorithms, but -1 for adding a dependency.

+1 by all means if you can improve the algorithms in [math] by
borrowing from Jama, patches are welcome.  Some of the [math] linear
algebra algorithms are already adapted from Jama. 

Phil
>
> On Tue, Jul 5, 2011 at 1:38 PM, Chris Nix <ch...@gmail.com> wrote:
>
>> CM is a great package, but I email to inquire if could we could solve
>> easily
>> the issues above by simply implementing public-domain JAMA-like code within
>> the linear algebra sub-package or, perhaps more controversially, have JAMA
>> as a dependency to CM?
>>
>> Is 'home-grown' code over public-domain code an objective of Commons Math?
>>  Like I say, it's a bold question.
>>


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Re: [math] Incorporating JAMA code to solve problems?

[Ted Dunning <te...@gmail.com>]

JAMA definitely is good algorithm wise.  API wise, it is very tied to a
single representation which isn't acceptable.

If you are finding JAMA more stable, then I would be +1 (in my own
non-binding way) for copying the algorithms, but -1 for adding a dependency.


On Tue, Jul 5, 2011 at 1:38 PM, Chris Nix <ch...@gmail.com> wrote:

> CM is a great package, but I email to inquire if could we could solve
> easily
> the issues above by simply implementing public-domain JAMA-like code within
> the linear algebra sub-package or, perhaps more controversially, have JAMA
> as a dependency to CM?
>
> Is 'home-grown' code over public-domain code an objective of Commons Math?
>  Like I say, it's a bold question.
>