Re: GSoC 2016 project idea - implementation of ode15s

[Richard Crozier]

On 06/03/16 15:25, Sebastian wrote:
> > Am 06.03.2016 um 12:17 schrieb Richard Crozier <address@hidden>:
> >
> > On 05/03/16 19:38, Sebastian Schöps wrote:
> > > Nir Krakauer-2 wrote
> > > > Hi Richard,
> > > >
> > > > I would be willing to be a co-mentor of this if/when we have a suitable
> > > > student. Can you please add the project description to ​
> > > > http://wiki.octave.org/Summer_of_Code_Project_Ideas ?
> > > >
> > > > Nir
> > >
> > > It's already there.
> >
> > Thanks for offering to mentor Nir, this would be great. I would do my best to 
> > help with all the 'boring' stuff like mercurial and setting up for octave 
> > development etc.
> >
> > Sebastian, there is no specific project to implement ode15s, it's mentioned in 
> > the Matlab Compatible DAE, but I don't think ode15s is a DAE solver?
>
> from the wiki: "The goal is to implement a Matlab compatible adaptive BDF solver for 
> Differential Algebraic Equations (DAEs). The interface would need to be compatible with 
> ode15s while for the backend the SUNDIALS library would be used, which has both a C and a 
> MEX interface. This function should eventually be included in Octave core together with 
> the other ODE solvers that will be released with version 4.2, but could be intially 
> developed as an addition to the odepkg package."
>
> > Perhaps you are thinking of ode15i? ode15s is a stiff ode solver.
>
> Both ("s" and "i") use the same BDF method and can be used for DAEs and (stiff) ODEs. 
> However "i" is more tailored for implicit DAEs, i.e., f(x',x,t)=0 instead of M*x'=f(x,t).
>
> Seb.

Thanks, it wasn't clear to me that this project aims to result in an 
implementation of ode15s, even though it's mentioned in the description. 
Mainly because I didn't think of it as a DAE solver (I've outlined my 
level of knowledge of the solvers already though).

I do wonder if fully implementing, and thoroughly testing a good, ML 
compatible version of ode15s isn't a fairly substantial project on it's 
own, but you'll have a much better idea of the work involved in this.

Richard

--
The University of Edinburgh is a charitable body, registered in
Scotland, with registration number SC005336.