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What Is Fuzzy Logic?

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2 Tutorial<br />

anfis and the ANFIS Editor GUI<br />

In this section...<br />

“Introduction” on page 2-106<br />

“A Modeling Scenario” on page 2-107<br />

“Model Learning and Inference Through ANFIS” on page 2-107<br />

“Know Your Data” on page 2-108<br />

“Constraints of anfis” on page 2-110<br />

“Training Adaptive Neuro <strong>Fuzzy</strong> Inference Systems Using the ANFIS<br />

Editor GUI” on page 2-110<br />

“ANFIS Editor GUI Example 1: Checking Data Helps Model Validation” on<br />

page 2-114<br />

“ANFIS Editor GUI Example 2: Checking Data Does Not Validate Model”<br />

on page 2-124<br />

“anfis from the Command Line” on page 2-128<br />

“More on anfis and the ANFIS Editor GUI” on page 2-134<br />

Introduction<br />

The basic structure of the type of fuzzy inference system seen thus far is a<br />

model that maps input characteristics to input membership functions, input<br />

membership function to rules, rules to a set of output characteristics, output<br />

characteristics to output membership functions, and the output membership<br />

function to a single-valued output or a decision associated with the output.<br />

You have considered only fixed membership functions that were chosen<br />

arbitrarily. You have applied fuzzy inference to only modeling systems whose<br />

rule structure is essentially predetermined by the user’s interpretation of the<br />

characteristics of the variables in the model.<br />

In this section we discuss the use of the function anfis and the ANFIS<br />

Editor GUI in the toolbox. These tools apply fuzzy inference techniques to<br />

data modeling. As you have seen from the other fuzzy inference GU<strong>Is</strong>, the<br />

shape of the membership functions depends on parameters, and changing<br />

these parameters change the shape of the membership function. Instead of<br />

just looking at the data to choose the membership function parameters, you<br />

2-106

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