Re: [ESPResSo-users] Force scaling wrong

[Henri Menke]

Dear Marcello,

you have a valid point point there, but…

The integrator does not overwrite forces if you use 'integrate <intsteps>
reuse-forces'.  Setting them by hand still does not make much sense for a
production run.  The possibility to set them by hand might still be useful for
testing purposes (i.e. a developer feature).  Furthermore the force setting
routines use by the TCL interface are also used by the blockfile reading
mechanism, hence a wrong scaling of forces in the interface leads to a wrong
scaling in the values read from a blockfile.

Thus I think, that if forces should be made read-only is another question.

Kind regards,
Henri


On Sat, Feb 28, 2015 at 08:36:15AM +0100, Marcello Sega wrote:
> Hi,
> 
> please correct me if I'm wrong: I think that forces are always
> overwritten by the integrator, so that setting them by hand does not
> have any effect at all.
> 
> If this is right, then allowing to set forces could be just misleading
> (as the program would behave in a way unexpected by the user).
> Wouldn't it be better to make them read-only?
> 
> Regards,
> 
> Marcello
> 
> 
> 
> 
> 
> 
> On Fri, Feb 27, 2015 at 3:56 PM, Henri Menke <address@hidden> wrote:
> > Dear all,
> >
> > in the current master of ESPResSo the forces are scaled by the masses
> > and the time step in the output, i.e. part 0 print f, but are not scaled
> > by the mass in the input, i.e. part 0 f.  This leads to wrong forces
> > when setting them by hand with a mass not equal to 1.
> >
> > This bug is fixed in the pull-request
> >
> >   https://github.com/espressomd/espresso/pull/213
> >
> > Kind regards,
> > Henri
> >
> 
> 
> 
> -- 
> Institut für Computergestützte Biologische Chemie
> University of Vienna
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