yade-dev team mailing list archive

[boon chiaweng <booncw@xxxxxxxxxxx>]

Hi, 

I've enabled LOG_INFO.  The computed timestep is ridiculously large.  Can somebody advise me how do i progressively track down the cause?

36697 [0x7f1eecb81950] INFO yade.GlobalStiffnessTimeStepper null - /home/chiab/yadeNew/Branch3/pkg/dem/Engine/GlobalEngine/GlobalStiffnessTimeStepper.cpp:170 computeTimeStep: computed timestep 7.56436e+153, BUT timestep is 7.59375.


Yours,

CWBoon


From: booncw@xxxxxxxxxxx
To: yade-dev@xxxxxxxxxxxxxxxxxxx
Date: Mon, 11 Jan 2010 19:52:20 +0800
Subject: Re: [Yade-dev] [Bug 505523] Re: Velocity Bin











Thanks Bruno. (Sorry, I forgot to clicked Reply All the first time).   I'm using a relatively new version right before 'bex' is changed to 'fex'.  I have looped through in python:

for b in O.bodies:
    if b.shape.name == 'Sphere':
        if b.shape['radius']<0.0001:
             print b.shape[radius]

Since
nothing appears, all my radius are positive.  I've also checked the
smallest radii range at the start of the simulation before expansion. 
The radius of the smallest particles are between 0.005 and 0.006.  The
weird thing is that the step size at the start of the simulation is as
large as 200000.  I've included a screenshot
  

Yours,

Boon

> Date: Mon, 11 Jan 2010 11:53:04 +0100
> From: bruno.chareyre@xxxxxxxxxxx
> To: yade-dev@xxxxxxxxxxxxxxxxxxx
> Subject: Re: [Yade-dev] [Bug 505523] Re: Velocity Bin
> 
> Hi Boon,
> 
> Are you sure your distribution is not giving negative radii or 
> something? The timestep is really (should be) the dt obtained on the 
> smallest particle. Or there is a bug in this old release.
> 
> Bruno
> 
> > Some particles are really small.  But everytime i run a simulation, it
> > gives me a different timestep.  And sometimes it is very large, because
> > I have very large particles in the simulation.  But the calculation of
> > the timestep should be based on the smallest particle.
> >   
> 
> 
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