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What Is Fuzzy Logic?

What Is Fuzzy Logic?

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anfis<br />

Purpose<br />

Syntax<br />

Description<br />

Training routine for Sugeno-type <strong>Fuzzy</strong> Inference System (MEX only)<br />

[fis,error,stepsize] = anfis(trnData)<br />

[fis,error,stepsize] = anfis(trnData,initFis)<br />

[fis,error,stepsize] = anfis(trnData,numMFs)<br />

[fis,error,stepsize,chkFis,chkErr] = ...<br />

anfis(trnData,initFis,trnOpt,dispOpt,chkData,optMethod)<br />

[fis,error,stepsize,chkFis,chkErr] = ...<br />

anfis(trnData,numMFs,trnOpt,dispOpt,chkData,optMethod)<br />

This syntax is the major training routine for Sugeno-type fuzzy inference<br />

systems. anfis uses a hybrid learning algorithm to identify parameters<br />

of Sugeno-type fuzzy inference systems. It applies a combination of<br />

the least-squares method and the backpropagation gradient descent<br />

method for training FIS membership function parameters to emulate a<br />

given training data set. anfis canalsobeinvokedusinganoptional<br />

argument for model validation. The type of model validation that takes<br />

place with this option is a checking for model overfitting, and the<br />

argument is a data set called the checking data set.<br />

The arguments in the description for anfis are as follows. Note<br />

that you can specify the arguments trnOpt, dispOpt, chkData, and<br />

optMethod as empty, [], when necessary:<br />

• trnData: the name of a training data set. This matrix contains data<br />

input in all but the last column. The last column contains a single<br />

vector of output data.<br />

• initFis: the name of a fuzzy inference system (FIS) used to provide<br />

anfis with an initial set of membership functions for training.<br />

Without this option, anfis uses genfis1 to implement a default<br />

initial FIS for training. This default FIS has two membership<br />

functions of the Gaussian type, when it is invoked with only one<br />

argument. If initFis is provided as a single number (or a vector),<br />

it is taken as the number of membership functions (or the vector)<br />

whose entries are the respective numbers of membership functions<br />

associated with each respective input when these numbers differ<br />

for each input). In this case, both arguments of anfis are passed<br />

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