[GiNaC-list] GiNaC and Scilab

[Jens Vollinga]

Hi,

Jorge Cardona schrieb:
> Well, about integrals i check the source and found a little piece of
> code that expands integrals (integrals.cpp) and resolve integrals on
> pow types, and with it solve polynomial integrals.
> 
> I was thinking in start there to add more methods, but i want to know
> if there is some work already done.

Nobody is working on that part at the moment. The integration code in 
integral.{h,cpp} is everything that exists.

> One way could be to add an argument to REGISTER_FUNCTION and pass an
> integral_func(...)  as the extra argument, and we have then integrals
> for all the functions registered, and we can then start to use more
> heuristic methods on integrals.cpp, well thats just an initial idea, i
> want to know all the previous ideas on it to start to work. With

Sounds good.

> I'm reading some papers on ACM Digital Library about symbolic
> integration, specially Symbolic integration: the stormy decade, and
> the one that is linked at the TODO list(that link is actually broken:
> http://www-sop.inria.fr/cafe/Manuel.Bronstein/publications/issac98.pdf).

Another good source might be:

O.I. Marichev. Handbook of integral transforms of higher transcendental 
functions: theory and algorithmic tables.

The method outlined in this book is very different from the Bronstein 
way of doing things, but for a lot of integrands it seems to be the best 
method. But maybe it is too unwieldy to be implemented in GiNaC (needs 
quite some tables).

> Well, i really want to add these features to GiNaC and then use it on
> scilab, please let me know everything about it, what do you expect of
> it? what basic guidelines on code writing, basic ideas, anything.

It'd be great if you could implement such functionality! My expectations 
  are only, that you write using the code style of the GiNaC code base 
(it should roughly look the same), and that the code is maintainable by 
other developers as well (keep it easy and documented). Man-power is 
always limited and code does rot ...

Other likely upcoming GiNaC developments are: symbolic summation (expect 
classes for sums), some code face-lifting in the polynomial/factor 
sector and polylog code. But nothing of this should interfere with your 
efforts.

Regards,
Jens