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Convert type-2 fuzzy inference system into type-1 fuzzy inference system

Since R2019b



fisT1 = convertToType1(fisT2) converts the type-2 fuzzy inference system fisT2 into a type-1 fuzzy inference system fisT1.


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Create a type-2 fuzzy inference system. For this example, Create a type-2 Mamdani FIS with two inputs, one output.

fisT2 = mamfistype2("NumInputs",2,"NumOutputs",1);

View the membership function for the first input variable.


Convert fisT2 into a type-1 fuzzy inference system.

fisT1 = convertToType1(fisT2);

View the converted membership functions for the first input variable.


Input Arguments

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Type-2 fuzzy inference system, specified as a mamfistype2 or sugfistype2 object.

Output Arguments

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Type-1 fuzzy inference system, returned as one of the following:

  • mamfis object when fisT2 is a mamfistype2 object

  • sugfis object when fisT2 is a sugfistype2 object

The properties of fisT1 match the corresponding properties of fisT2, except that each type-2 membership function is converted to a type-1 membership function. The parameters of each type-1 membership function in fisT1 match the upper membership function parameters of the corresponding type-2 membership function in fisT2.

Alternative Functionality


You can interactively convert a type-2 FIS into a type-1 FIS using the Fuzzy Logic Designer app. You can then export the system to the MATLAB® workspace.

Version History

Introduced in R2019b