On Fri, 03 Aug 2001 17:41:12 GMT, predictr@bellatlantic.net wrote:> Here is a simple fuzzy logic system, borrowed from an example given in > "The Fuzzy Systems Handbook", by Earl Cox. The problem is to establish > the price of a product. The fuzzy system has 4 rules: > > 1. The price should be high > 2. The price must be low > 3. The price must be around 2 times cost > 4. If the competition price is not very high, then the price should be > near the competition price > > Mathematical definitions terms like "high", "low", "near the competition > price" etc. are part of this fuzzy system, which yields a suggested > price. These rules are in fact part of a system which has been used to > price millions of dollars worth of real products for a profit-making > enterprise. This fuzzy system solves the problem for which it was intended. > > My question to fuzzy critics is: why should this system not be used?
I stopped by the library and thumbed through Cox's book. I checked out a book of "Practical applications ..." instead, because Cox's seemed to be filled with toy problems. The example above doesn't seem very serious, either. Let me see: My answer starts with tossing out (1) and (2) as, not only fuzzy but directly in conflict. Then I settle for round numbers. ===== answer a) Set the price at the average of < competitor's price> and < 2 times cost> if those quantities are not more than 25% apart. b) If they are farther apart, scream for help. ===== end answer I am willing to be instructed. I said before, something like, commercial solutions I've heard of were (it seemed) victories for glib salesmen, not for science. What's the fuzzy solution? Is the "fuzzy" answer more precise than mine? Does the fuzzy answer include a warning/diagnostic against heterogeneity, that plays the role of my (b)? -- Rich Ulrich, wpilib@pitt.edu http://www.pitt.edu/~wpilib/index.html