commons-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Sébastien Brisard <sebastien.bris...@m4x.org>
Subject Re: [math] extend FieldElement<T>
Date Mon, 09 May 2011 18:30:20 GMT
Le 09/05/11 19:52, Luc Maisonobe a écrit :
> Le 09/05/2011 09:15, Arne Plöse a écrit :
>> Hi,
>>
>> here are some proposals for enhancing FieldElement<T>:
>>
>> add some shorthand "operators" for double i.e. add(double rhs) ... and
>> so on.
>>
>> add:
>> T negate();
>> T sqrt();
>> T pow(T x);
>> T pow(double x);
>
> This is possible only for negate() in the FieldElement<T>. Not all 
> fields support sqrt or pow. A typical example is Fraction, the square 
> root of a fraction may not be a fraction for example.
>
> This is exactly this limitation that explains while only LU 
> decomposition is implemented for fields and not other decomposition 
> algorithms.
>
> One possibility would be to add an ExtendedFieldElement<T> interface 
> that would add these methods for the fields that support it (Complex, 
> Dfp ...). Then, we could add new decomposition algorithms that would 
> work on these extended fields (but still not on simpler fields like 
> fraction.
>
This looks to me a lot like Jscience (jscience.org). This is an 
excellent library, I've been using a little recently.
Sebastien
>>
>> the FieldVector interface should be enhanced with this methods as well.
>>
>> Yes, I know this has an impact on many classes ....
>
> This is not really a problem, especially as we are defining a new 
> major release, it is exactly the right time to propose such extensions.
>
> Luc
>
>>
>> Arne
>>
>>
>> ---------------------------------------------------------------------
>> To unsubscribe, e-mail: dev-unsubscribe@commons.apache.org
>> For additional commands, e-mail: dev-help@commons.apache.org
>>
>>
>
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: dev-unsubscribe@commons.apache.org
> For additional commands, e-mail: dev-help@commons.apache.org
>
>


---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscribe@commons.apache.org
For additional commands, e-mail: dev-help@commons.apache.org


Mime
View raw message