Dear DDJ,
I was disappointed to read Peter Roth's review of my book, The Design and Development of Fuzzy Logic Controllers, in the May 1998 issue of DDJ. I feel that the coverage of my book was simplistic and harsh. Although there is an editorial error in the graphs on pages 2 and 3, which has been corrected in a subsequent printing, I feel it does not detract from the overall content of the book.
Readers who take time to go beyond a cursory inspection of the book would understand what Mr. Roth calls an "unintelligible 3D graph" (page 36) is used as an aid to interpret the FuzzzyStat system's behavior. The graph is explained previously on page 33, using terminology defined earlier ("Control Surface Plots," page seven) in the book. Similarly, the "several unintelligible input files" referred to in the review are used by the TeachFuzz fuzzy logic simulator, which is discussed on page 24.
Further, what Mr. Roth refers to as "opaque graphs" are actually the accompanying control surfaces for each of the simulated models. Keep in mind, each fuzzy logic simulation tool has its own unique input file format and the TeachFuzz fuzzy logic simulator is no different. For example, Motorola's Fuzzy Inference Development Environment (FIDE) has a similar structure, requiring multiple input files.
Additionally, I would disagree with Mr. Roth's criticism of the fuzzy logic development cycle (Figure 3.2, page 45). Although the explanation of this diagram is abbreviated for the reader, it is truly a spiral model, not a waterfall model as he states. The difference being that a traditional software waterfall model feeds back to the preceding phase rather than feeding back on itself, or all the way back to the requirements phase. I would refer Mr. Roth to the book Software Engineering by Stephen Schach, as cited in the book's references, for a more detailed explanation of the software development lifecycle model.
Mr. Roth does point to several strengths of the content of the book, including the number of interesting fuzzy logic controller projects presented in the book and the "clear survey" of fuzzy logic. Given these comments, his closing statements about the book are puzzling at best, and highly inaccurate at worst. I encourage readers to evaluate the book for themselves.
Byron Miller
impub@isd.net