Hi,
As far as I know there should be a short
explanation in the OpenModelica Users's guide.
That being said, here is a crash course:
- The step size is calculated with:
(stopTime-startTime)/numberOfIntervals = step size
The defaults are:
startTime=0, stopTime=1, numberOfIntervals=500
- The tolerance tells the dassl solver how accurately
it should try to do the numerical integration.
The default: tolerance=10e-10 which is a bit high as
for example Dymola has a tolerance of 10e-3 by default
and MathModelica System Designer one of 10e-4.
Well I hope this answers your questions a bit.
Cheers,
Adrian Pop/
[EMAIL PROTECTED] wrote:
Thanks a lot Adrian. It actually works (from many hours to a few
minutes!). I have been looking on the openmodelica documentation for
some info on simulation parameters (e.g., tolerance and
numberOfIntervals), like what they control and how to properly set
them, but I haven't found too much. Could you please suggest a
reference where I can find this info? Thanks again for your help,
Massimiliano
---------- Initial Header -----------
From : [EMAIL PROTECTED]
To : [email protected] Cc : Date
: Thu, 21 Aug 2008 22:38:28 +0200 Subject : Re: omc
+d=interactiveCorba slow simulation
[EMAIL PROTECTED] wrote:
Hi guys, I developed a model with openmodelica, and I am running
it by calling the "simulate" command through a CORBA connection.
Now, everything works fine (connection, model, etc...), but the
simulation is extremely slow (getting results with the "val(..)"
service, at the end of the simulation, also takes long sometime).
The model is quite large, but if I run it in OMNotebook the
simulation is much faster (clearly, no interaction is allowed in
this case). Does anyone have this problem? Is the "interactive
mode" known to be much slower? Do you have any suggestion to
speed up the simulation in corba mode? Many thanks in advance for
any suggestion. Cheers, Massimiliano
Hi,
This sounds strange as OMNotebook runs omc +d=interactiveCorba in
the background and when you evaluate the cell it will actually send
the command to the OMC compiler via Corba and get the results back.
The simulation should take the same time if you run in OMNotebook
or via any other Corba connection (OMShell for example).
You could make the simulation time take less only if you play with
parameters of the simulation command: simulate(Model, stopTime=1,
tolerance=10e-3, numberOfIntervals=20);
Cheers, Adrian Pop/
