octave-maintainers
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: More help with odeset()


From: c.
Subject: Re: More help with odeset()
Date: Wed, 19 Oct 2016 14:22:52 +0200

Hi,

On 18 Oct 2016, at 21:16, Rik <address@hidden> wrote:

> Could someone run the following test under Matlab?
> 
> x = odeset ('MassConstant', true)
> 
> According to the documentation in Octave,
> 
> ## @item MassConstant
> ## Specify whether the mass matrix is a constant matrix or depends on
> ## the state.
> 
> but this option doesn't appear in the Matlab documentation for odeset. 

> It's probably unnecessary because when the Mass property is a matrix, it is
> constant, if Mass is a function handle, it has the possibility of depending
> on state. 

Indeed, but I think the idea behind the MassConstant is that the Mass matrix 
can depend on time but not on state or be completely constant and even a 
constant 
matrix could be passed as a function that builds the matrix.

This option is not available in Matlab now but was present in previous versions
as can be seen from old sites discussing the matlab odesuite, e.g.:

http://cens.ioc.ee/local/man/matlab/techdoc/ref/odeset.html

It is hard to determine in what version it was removed.

We decided to keep other functionalities of odepkg for backward compatibility
with cruft matlab code, we may decide to keep this one as well, I do not have 
any
strong feeling about this.

> If it isn't necessary it can be deleted and the FIXME in the code for
> odeset closed.  I tried 'grep -r MassConstant' in scripts/ode and the
> property isn't used in any calculating solver.


I can't seem to find any use of this in odepkg either.

> --Rik


c.





reply via email to

[Prev in Thread] Current Thread [Next in Thread]