[kepler-dev] How do I create nested loops in Kepler

[Bertram Ludaescher]

Edward:

This is very interesting and I'd like to get a hold of it.
Maybe one of your students could scan it and creat a PDF version!? 

Also, in reply to Dan's comment:

 > >I've tried various ways using Ramp actors and Composite actors but
 > >cannot seem to get this simple case to work.

I guess that this is not as simple a case as one might wish (in simple
dataflow and/or block diagram languages).. just like doing procedural
loops in functional or logic programming is tricky (and one has to use
recursive patterns instead)

Probably Edward's paper will be very instructive in dealing with these
issues. Also, I think there are nice new opportunities for doing
procedural stuff nicely in Kepler by using Ptolemy's state machines...

Bertram




Edward A. Lee writes:
 > 
 > Dan:
 > 
 > This is a very good question. In fact, I wrote a paper once on this
 > subject:
 > 
 > E. A. Lee, "Recurrences, Iteration, and Conditionals in Statically
 > Scheduled Block Diagram Languages," in VLSI Signal Processing III,
 > Ed. R. W. Brodersen and H. S. Moscovitz, IEEE Press, New York, 1988.
 > 
 > This paper is not on the web, although I could get you a copy if you like...
 > 
 > For your example, the attached model illustrates one simple technique.
 > It also elaborates on it, producing the iteration indices for both
 > the outer an inner iterations. There are also much more elaborate
 > models one can create using higher-order components, like the
 > IterateOverArray actor and many others that we haven't gotten
 > around to porting from Ptolemy Classic...
 > 
 > Edward
 > 
 > 
 > 
 > At 03:58 PM 7/5/2005 -0700, Dan Higgins wrote:
 > >Hi All,
 > >
 > >     I am having great difficulty in figuring out how to handle various
 > >looping constructs in Kepler/Ptolemy. So I ask if someone can explain
 > >how to handle nested loops (using SDF and/or PN directors)?
 > >
 > >     For example, assume I want to count from 0 to 3 twice in a row so
 > >that the output on a final text display is
 > >0
 > >1
 > >2
 > >0
 > >1
 > >2
 > >
 > >I've tried various ways using Ramp actors and Composite actors but
 > >cannot seem to get this simple case to work.
 > >
 > >Thanks,
 > >Dan
 > >
 > >--
 > >*******************************************************************
 > >Dan Higgins                                  higgins at nceas.ucsb.edu
 > >http://www.nceas.ucsb.edu/    Ph: 805-893-5127
 > >National Center for Ecological Analysis and Synthesis (NCEAS)
 > >Marine Science Building - Room 3405
 > >Santa Barbara, CA 93195
 > >*******************************************************************
 > >
 > >_______________________________________________
 > >Kepler-dev mailing list
 > >Kepler-dev at ecoinformatics.org
 > >http://mercury.nceas.ucsb.edu/ecoinformatics/mailman/listinfo/kepler-dev
 > 
 > ------------
 > 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
 > eal at eecs.Berkeley.EDU, http://ptolemy.eecs.berkeley.edu/~eal  _______________________________________________
 > Kepler-dev mailing list
 > Kepler-dev at ecoinformatics.org
 > http://mercury.nceas.ucsb.edu/ecoinformatics/mailman/listinfo/kepler-dev