Researcher: Dr. Brian L. Evans
Supervisor: Prof. Edward A. Lee
Sponsor: ARPA and the US Air Force (under the RASSP program, contract
F33615-93-C-1317)
Title: Interoperability of Special-Purpose Tools with Ptolemy
This project is part of a larger research program for developing rapid
prototyping tools for the specification, simulation, and synthesis of
embedded signal processors [1-2]. We are testing rapid prototyping ideas
within the Ptolemy environment which has been under development since
1990. Ptolemy describes systems as hierarchical block diagrams.
This goal of this project is to connect special-purpose symbolic analysis
tools (e.g. Mathematica) to aid in system specification and special-purpose
numeric processing tools (e.g. Matlab) to aid in simulation. Matlab is
commonly used for prototyping signal processing algorithms because of its
signal and image processing toolboxes and its visualization capabilities.
Matlab algorithms can be imported into Ptolemy. In Ptolemy, a Matlab block
represents a sequence of Matlab commands to be applied to the block's input
signals to produce output signals. We are refining this interface, which is
part of Ptolemy, version 0.5.1, released in September of 1994.
Mathematica is a symbolic algebra system. By itself, it can assist designers
in deriving and analyzing values of free parameters, especially when the
values of parameters are defined in terms of other parameters that are not
known until run time. By using the signal processing packages [3-5] for
Mathematica, designers can apply rules to generate new and redesign
synchronous dataflow graphs. (Synchronous dataflow is a computational model
which processes computations on uniformly sampled data.) We are working on
exchanging system descriptions between Ptolemy (which uses flow graphs) and
the Mathematica signal processing packages (which uses algebraic equations).
[1] A. Kalavade, B. L. Evans, J. L. Pino, and E. A. Lee, "Managing
Complexity in Heterogeneous Specification, Simulation, and Synthesis,"
invited paper, Proc. of IEEE Int. Conf. on Acoustics, Speech, and
Signal Processing, May, 1995, Detroit, MI.
[2] B. L. Evans, A. Kamas, and E. A. Lee, "Design and Simulation of
Heterogeneous Systems Using Ptolemy," First Annual Rapid Prototyping of
Application Specific Signal Processors (RASSP) Conference, Arlington, VA,
Aug. 15-18, 1994, pp. 97-105.
[3] B. L. Evans, J. Teich, and C. Schwarz, "Automated Design of
Two-Dimensional Rational Decimation Systems," Proc. of IEEE
Asilomar Conf. on Signals, Systems, and Computers, Oct. 31 - Nov. 2,
Pacific Grove, CA, 1994.
[4] B. L. Evans, T. R. Gardos, and J. H. McClellan, "Imposing Structure on
Smith Form Decompositions of Rational Resampling Matrices", IEEE
Trans. on Signal Processing, vol. 42, no. 4, pp. 970-973, April, 1994
[5] B. L. Evans, "A Knowledge-Based Environment for the Design and Analysis
of Multidimensional Multirate Signal Processing Algorithms", Georgia
Institute of Technology, Atlanta, GA, June, 1993.