[SciPy-Dev] Delay Differential Equation (DDE) solver

[Ralf Gommers]

On Sun, May 17, 2020 at 1:41 PM Jansen Jérôme <jrme.jansen at gmail.com> wrote:

> My dear SciPy community,
>
> In my PhD, I work on biomechanical problematics which are (sometime)
> modeled with delay differential equations.
> Being an avid user of python and SciPy, I looked for DDEs solver but ... I
> was surprised not to find it in SciPy. On the contrary, I discovered lots
> of more or less old and very different projects about DDEs in Python
> (JiTCDDE, ddeint, pydelay, diffeqpy). While in other programming languages,
> robust code exist (matlab: dde23, julia: DelayDiffEq.jl, fortran: DKLAG6
> ...).
> So I decided to start implementing a solver using the architecture of
> scipy.integrate.solve_ivp.
>
> The fork us here :
> https://github.com/jrmejansen/scipy/tree/ddeSolver
>
> I added the folder "*scipy/integrate/_dde*" and modified files from
> "scipy/integrate/_ivp" to resolve DDEs. You would find also some benchmarks
> but not yet unit tests.
>
> At this time, the solver, *solve_dde*, handles DDEs with constant delays
> for none stiff equations.
>
> Does my code interest the SciPy community ?
> If it does, I can add extensive unit tests and also docstring.
>

Hi Jérôme, thanks for proposing this. Having a good DDE solver would be
quite nice. I've certainly missed it in the past. The difficulty here is
that it is fairly niche, and we'd need to find someone to review the PR.
scipy.integrate is already struggling a bit with lack of maintainers. Also,
we need to think about future maintenance - if you would be willing to
continue to maintain it, that would certainly help.

We did have a feature request open for a long time, but there wasn't too
much interest it looked like: https://github.com/scipy/scipy/issues/818

So first question would be, is there someone else - either a SciPy
maintainer or a domain expert - who is interested in helping to get this
merged?

Best,
Ralf


> I am open to any discussion and do not hesitate to give me feedbacks.
> Best regards,
> Jérôme JANSEN.
> _______________________________________________
> SciPy-Dev mailing list
> SciPy-Dev at python.org
> https://mail.python.org/mailman/listinfo/scipy-dev
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/scipy-dev/attachments/20200520/99e153c2/attachment.html>