[ODE] eliminating all state

[nlin@nlin.net]

On Thu, Nov 21, 2002 at 05:24:02PM -0700, Russ Smith wrote:
> >  Russ, you mentioned that ODE uses the correction at one timestep to
> > estimate the size of the correction at the next timestep.  Is there any
> > way I can reset this between evaluations?  Is there anywhere else state is
> > stored?
> 
> i hope i didn't mention this, because its not true. each time step is
> completely independent from the last ... the only information that flows
> between time steps is the position, orientation and linear/angular
> velocity of the bodies. but of course all the ODE parameters will have
> effects that spread throughout time precisely because they affect the
> positions/velocities.

Russ,

The message from which you are being indirectly quoted is:

http://q12.org/pipermail/ode/2002-April/001107.html

The relevant passage:

On Wed, Apr 10, 2002, Russ Smith wrote:
> in the small-large
> timestep case it fails, because the velocity correction is timestep
> dependent (i.e. the small velocity correction calculated during the
> small timestep becomes a much-too-large correction during the large
> timestep). there is a good fix for this problem, which i will
> eventually add to ODE (as time permits). there'll be a dWorld switch
> to turn it on, as there is a slight performance cost.

Has the "fix" mentioned above been implemented? What is the idea behind
the fix?

-Norman