William Stein a écrit :
> On Fri, Dec 18, 2009 at 11:53 PM, Thierry Dumont
> <tdum...@math.univ-lyon1.fr> wrote:
>> Carlos Córdoba a écrit :
>>> Hi,
>>>
>>> I know this is not a general mathematical forum, but I hope you can help me.
>>> I have this PDE:
>>>
>>> \frac{dB}{dt} = F(x,y,z)B(x,y,z) - G(x,y,z)\nabla B(x,y,z)
>>>
>>> and I don't know how to solve it numerically. What would be the easiest
>>> method to do it? It can be in python, but preferably in C++.
>>>
>>> Thanks for your help,
>>> Carlos
>>>
>> Hi,
>>
>> 1) You will not find in Sage what you are looking for; this is not the
>> place and as a specialist of numerics for PDEs, I think it will remain
>> like this.
>
> No it won't :-)
>
>> 2) You problem is not so easy: it is a first order equation of
>> hyperbolic type and this is not easy to solve. For example the problem
>> du/dt+du/dx=0, for which we have an exact solution is not easy to solve
>> numerically (at least one must process with care to avoid
>> instabilities). Your problem is a bit more complicated. Solving the heat
>> equation for example is much more easy.
>> 3) for numerics on these first order problems, have a look at clawpack:
>> it solves much more complicated problems (first order non linear
>> systems- like gas dynamics for example), but it will solve easily your
>> problem. You will have to know some bases on the numerical analysis of
>> hyperbolic pde.
>> http://www.amath.washington.edu/~claw/
>
> For the record, I recently worked with the authors to get them to
> change the license of clawpack to be GPL-compatible and know the
> people who work on that project (who are at the same university as
> me).
>
> William
>
Ok! great. My position is only that I do not think that Sage will be the
good place to solve true life large PDE systems (industrial problems, 3d
problems), but integrating clawpack would be great for teaching. This is
*only* my *personal* vision of this.A question about numerics in Sage: what about pydstool ? http://www.cam.cornell.edu/~rclewley/cgi-bin/moin.cgi/ (this is a tool for dynamical systems, bufurcations and so on). Is anybody working on an integration in Sage ? t.d. -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
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