Contents:
Ptolemy II 10.0 is the first complete release since Ptolemy II 8.0 and thus includes many changes.
The key driving force for the release is to be a companion to the Ptolemy Book:
Claudius Ptolemaeus, Editor, "System Design, Modeling, and Simulation Using Ptolemy II", Ptolemy.org, 2014. (included in the release as $PTII/doc/books/systems/PtolemyII_DigitalV1_02.pdf, but not present in the SVN developer tree.)
Below are the highlights of this release.
$PTII/doc/books/systems/PtolemyII_DigitalV1_02.pdf)Ptolemy II includes a flexible mechanism for creating web pages from models and for building web services. The more basic mechanism is the export to web , which simply makes a model available as a web page for browsing using a web browser. Such a web page provides easy access and documentation for models that archives both the structure of the models and the results of executing the models. It can be used to share information about models or their execution without requiring installation of any software, since an ordinary web browser is sufficient. More interestingly, the mechanism is extensible and customizable, allowing for creation of fairly sophisticated web pages. You can associate hyperlinks or actions defined in JavaScript with icons in a model. The customization can be done for individual icons in a model or for sets of icons in a model.
$PTII/doc/books/systems/PtolemyII_DigitalV1_02.pdf)Ptolemy II 10.0 includes the "cg" code generator at $PTII/ptolemy/cg.
We took the lessons learned from $PTII/ptolemy/codegen and applied them to cg. In particular, cg more easily supports multiple backends with less code duplication. The cg code generator is under active development, we are working on code generation for large systems. For details about cg, see $PTII/ptolemy/cg/README.html.
Developers: Christopher Brooks, Dai Bui, Bert Rodiers, Stavros Tripakis
$PTII/doc/books/systems/PtolemyII_DigitalV1_02.pdf)The Internet of Things is the idea that everyday objects are uniquely addressable and have a representation in a structure similar to the Internet.
Comparing and contrasting IoT with Cyber-physical Systems (CPS) is useful. The key thing with CPS is the interaction between the dynamics of the physical world and the dynamics of software and networks. The focus of IoT is on the information flow between physical devices and network services. In the Cyber-Physical Systems Concept Map, IoT overlaps with wireless sensing and actuating, though IoT is not necessarily wireless.
The name "Ptango" refers to the fact that with the Internet of Things, it takes more than two to tango.
The research goal of Ptango is to invent a Model of Computation (MoC) for the Internet of Things that assigns operational semantics to the composition of Things.
Applications and features of interest include:
Ptango is using Representational state transfer (RESTful) interfaces like http, which is stateless, where all the state is carried in the request and reply. Via RESTful interfaces, our work is focusing on a subset of IoT known as the Web of Things.
The JavaScript actor executes a script that can read inputs and parameters, perform calculations, and write outputs.
$PTII/doc/tutorial/domains$PTII/doc/tutorial/graph$PTII/doc/tutorial/guiant. Eclipse and ant are preferred over make because make is slower. To build using ant, see $PTII/doc/coding/ant.htm$PTII/pt-modules: Support for building OSGi modules of a subset of Ptolemy II: Hallvard TrættebergPatricia Derler, Chris Shaver, and Edward Lee have developed a starting point for a much smarter way of handling arrays in dataflow models...
In particular, there is now in the Array library an ArrayUpdate actor, whose output is the same array as its input except that one element is replaced with a new value. Please try it out for the radar model.
The key here is that this is done efficiently for large arrays. The input array does not get copied. Instead, the output array references the input array and encodes the diff. The input array is unchanged, and hence may be used safely by other actors to which it is destined without introducing nondeterminacy.
This is only a starting point because there are many other array operations that should be similarly encoded as diffs. There is a bit of work to be done here, and we need to make sure to be measuring performance effects.
The current implementation has the interesting property that makes copying arrays unnecessary most of the time. However, it has the unfortunate side effect of making copying arrays more expensive (we can no longer use the low-level System.arraycopy() mechanism in Java). It would be interesting to do a systematic performance evaluation of this. I believe that if we combine this method with a PN director and a manycore machine, that we might get good utilization of parallelism on the machine.
$PTII/ptolemy/actor/lib/aspect$PTII/ptdb (ptdb and ptserver use non-open source code, so we do not include the javadocs in the release)$PTII/ptserver$PTII/ptolemy/actor/injection$PTII/ptolemy/homer$PTII/ptolemy/actor/gui and $PTII/ptolemy/plotThe JavaScript actor executes a script that can read inputs and parameters, perform calculates and write outputs.
Wikipedia defines JSON as "JSON ... or JavaScript Object Notation, is an open standard format that uses human-readable text to transmit data objects consisting of attribute–value pairs. It is used primarily to transmit data between a server and web application, as an alternative to XML".
The JSON conversion actors convert between JSON and Ptolemy Tokens. As the type of the JSON input is not always known in advance, the notion of backward type conversion has been added to Ptolemy II by Marten Lohstroh.
To enable backward type conversion in Vergil, right click on the canvas, select Customize, then Configure, then check the enableBackwardTypeInference box.
$PTII/doc/books/systems/PtolemyII_DigitalV1_02.pdf)PDFAttribute to the Utilities->Decorative library in Vergil that allows you to include PDF in a Vergil diagram.
PDFAttribute can be used to include Latex-formatted equations in Vergil diagrams, and get full print resolution when printing to PDF for use in papers, books, etc.
PDFAttribute uses uses pdf-renderer, obtainable from https://pdf-renderer.dev.java.net/. This is a LGPL'd open source product from Sun.
To use PDFAttribute and create equations, we use LatexIt (see http://www.apple.com/downloads/macosx/math_science/latexit.html) for the Mac version) From LatexIt, we can create a PDF file with an equation.
Then drag into my Vergil diagram a PDFAttribute, or select Edit Custom Icon and drag in a PDFIcon. Double click on that to select the PDF file.
The Petrinet model computation was rewritten by Zach Ezzell of the University of Florida.
$PTII/ptolemy/domains/scr - The Software Cost Reduction model of computation: Patricia Derler$PTII/org/ptolemy/machineLearning/hmm - Hidden Markov Modeling$PTII/org/ptolemy/machineLearning/hmmAOM - Hidden Markov Modeling: Aspect-Oriented Modeling$PTII/org/ptolemy/machineLearning/particleFilter - Particle Filter$PTII/org/ptolemy/machineImprovisation - Machine ImprovisationFor the current list of bugs, see Ptolemy II Bugs
and Kepler Bugs.
A few features and classes were removed outright.
$PTII/ptolemy/codegen$PTII/ptolemy/cg instead.