Apologies for the delay in responding...
In the current version of Ptolemy II (accessible by CVS or by the
5.0-beta release or the imminent 5.0 release), there is a demo
in the tour called IncreasingRatePoisson that shows how to do this.
It gives the "exponential" version. To get the "uniform" version,
just change the action expression on the transition from the init
to the wait state. That expression currently reads:
wait.threshold = -log(1-random())
If you change it to, for example:
wait.threshold = random()
then the model will remain in the wait state for a random amount
of time that is uniformly distributed between 0 and 1.
Edward Lee
At 11:32 AM 6/30/2005 -0400, V P wrote:
Folks:
I would like to model a CT stochastic process as follows:
Two states - ON, and OFF with output values of 1 and 0 respectively
process randomly transitions from ON to OFF state.
duration of ON state should be exponentially distributed
duration of OFF state should be uniformly distributed
I am hoping that I can achieve this by modifying the three state
Continuous Clock example by Haiyang Zheng. Does this make sense? Are
there better ways to achieve what I want?
As a test, I deleted state3 in that example and changed the state2 -->
state1 transition guardExpression from " time == timeInterval" to
"time == timeInterval + random()" to make it random. I got the
following from the CT Director:
ptolemy.kernel.util.IllegalActionException: The refined step size is
less than the minimum time resolution, at time 3.7096332590000003
in .vj_ContinuousClock.CT Director
at
ptolemy.domains.ct.kernel.CTMultiSolverDirector._refinedStepWRTOutput(CTMultiSolverDirector.java:1257)
at
ptolemy.domains.ct.kernel.CTMultiSolverDirector._resolveInitialStates(CTMultiSolverDirector.java:1567)
at
ptolemy.domains.ct.kernel.CTMultiSolverDirector._continuousPhaseExecution(CTMultiSolverDirector.java:900)
at
ptolemy.domains.ct.kernel.CTMultiSolverDirector.fire(CTMultiSolverDirector.java:367)
at
ptolemy.domains.ct.kernel.CTMixedSignalDirector.fire(CTMixedSignalDirector.java:189)
at ptolemy.actor.CompositeActor.fire(CompositeActor.java:329)
at ptolemy.actor.Manager.iterate(Manager.java:601)
at ptolemy.actor.Manager.execute(Manager.java:319)
at ptolemy.actor.Manager.run(Manager.java:951)
at ptolemy.actor.Manager$2.run(Manager.java:1003)
Why am I getting this error? How can I avoid it?
Any help would be greatly appreciated.
Vijaya Poudyal
----------------------------------------------------------------------------
Posted to the ptolemy-hackers mailing list. Please send administrative
mail for this list to: [EMAIL PROTECTED]
------------
Edward A. Lee
Professor, Chair of the EE Division, Associate Chair of EECS
231 Cory Hall, UC Berkeley, Berkeley, CA 94720
phone: 510-642-0253 or 510-642-0455, fax: 510-642-2845
[EMAIL PROTECTED], http://ptolemy.eecs.berkeley.edu/~eal
----------------------------------------------------------------------------
Posted to the ptolemy-hackers mailing list. Please send administrative
mail for this list to: [EMAIL PROTECTED]
