Re: Odeset - Odeget

[Olaf Till]

On Sat, Aug 31, 2013 at 03:22:16AM +0000, Roberto Porcù wrote:
> Hi everybody,
> i'm working on the Octave Socis project and i developed a program which
> implements a geometric integrator for Hamiltonian systems; this solver
> is a spectral variational integrator. The goal is to add this function to
> OdePkg so i implemented that with the same signature of other functions of 
> this
> package, like ode45 whose arguments are (@functionHandle, time, 
> initial_conditions, odeset).
> My problem is that i need more options than those you can set with odeset,
> so that i need to define new fields in odeset struct. Till now i just added
> a new argument at the end, which is a struct containing these missing fields
> but i think it is not very nice.
> My idea is to modify the existing odeset function, adding the possibility to
> set the values of new fields that are not pre-established, just like a normal 
> struct.
> Is it reasonable or are there reasons that make it not possible?
> I will really appreciate your suggestions and observations.
> Thanks
> 
> Roberto

'odeset' and 'optimset' seem to be intended (in Matlab) to work
identically, only for different sets of options. So I'd suggest
copying core-Octaves 'optimset.m', 'optimget.m', and '__all_opts__.m',
just formally changing them a bit.

This done, each new function using odeset/get can define new options
within itself, without changing odeset anymore (by including something
like:

## PKG_ADD: __all_odeset_opts__ ("my_function");

and making 'my_function', if called with single argument "defaults",
return all options it uses. Octaves and some of optims optimization
functions are examples.)

This would probably require formally changing the other functions
already using odeset.

Of course new options should be chosen carefully (they might be
generally applicable), possibly discussing them before.

Thomas?

Regards,

Olaf

-- 
public key id EAFE0591, e.g. on x-hkp://pool.sks-keyservers.net

signature.asc
Description: Digital signature