Rule Base Reduction
Various attempts have been made over the years to reduce the rule base of a fuzzy
logic system. Rule base reduction may be important for computational reasons in
those cases where a fuzzy system has to be implemented in real time. Professor
Yeung Yam and his colleagues have recently published an algorithm  based on
singular value decomposition whereby a fuzzy rule base can be reduced.
Professor Simon's submitted paper  has demonstrated the technique on a fuzzy
estimator for motor winding current estimation, where the rule base was reduced
from 49 rules to 9 rules. This site makes general-purpose MATLAB code available for fuzzy rule base
reduction using Yam's algorithm. The code consists of two files that are zipped
up in the file Reduce.zip.
The two files in Reduce.zip are Reduce.m (the main file) and FuzzFunc.m (an
auxiliary file). Both files are necessary for the rule base reduction
algorithm. In order to run the rule base reduction algorithm, perform the
- Download the zip file by clicking
on the above link.
- Unzip Reduce.zip to get
Reduce.m and FuzzFunc.m. If you don't have software to unzip the file, you
can download a free evaluation version of WinZip from www.winzip.com.
- Run MATLAB and make sure that
the location of Reduce.m and FuzzFunc.m on your hard drive is part of your
MATLAB path. For example, if you downloaded the files to the c:\reduce
directory on your hard drive, type
at MATLAB's command prompt.
- Type "Reduce" at
the MATLAB prompt.
- D. Simon, “Design and Rule
Base Reduction of a Fuzzy Filter for the Estimation of Motor Currents,” International
Journal of Approximate Reasoning, vol. 25, pp. 145-167, October 2000 -
pdf, 373 KB
- Y. Yam, P. Baranyi, and C.
Yang, "Reduction of Fuzzy Rule Base Via Singular Value
Decomposition," IEEE Transactions on Fuzzy Systems, Volume 7,
Number 2, pp. 120-132, 1999.
- Y. Yam, "Fuzzy Approximation
Via Grid Point Sampling and Singular Value Decomposition," IEEE
Transactions on Systems, Man, and Cybernetics – Part B: Cybernetics,
Volume 27, Number 6, pp. 933-951, 1997.
Professor Simon's Home Page
Department of Electrical and Computer
Cleveland State University
Last Revised: December 13, 2013