What Is Fuzzy Logic?

2 Tutorial
Building Fuzzy Inference Systems Using Custom Functions
In this section...
“How to Build Fuzzy Inference Systems Using Custom Functions in the
GUI” on page 2-58
“Specifying Custom Membership Functions” on page 2-60
“Specifying Custom Inference Functions” on page 2-66
How to Build Fuzzy Inference Systems Using Custom
Functions in the GUI
When you build a fuzzy inference system, as described in “Overview of Fuzzy
Inference Process” on page 2-21, you can replace the built-in membership
functions or inference functions, or both with custom functions. In this
section, you learn how to build a fuzzy inference system using custom
functions in the GUI. To learn how to build the system using custom functions
at the command line, see “Specifying Custom Membership and Inference
Functions” on page 2-81 in “Working from the Command Line” on page 2-72.
To build a fuzzy inference system using custom functions in the GUI:
1 Open the FIS Editor by typing fuzzy at the MATLAB prompt.
2 Specify the number of inputs and outputs of the fuzzy system, as described
in “The FIS Editor” on page 2-35.
3 Create custom membership functions, and replace the built-in membership
functions with them, as described in “Specifying Custom Membership
Functions” on page 2-60.
Membership functions define how each point in the input space is mapped
to a membership value between 0 and 1.
4 Create rules using the Rule Editor, as described in “The Rule Editor” on
page 2-49.
Rules define the logical relationship between the inputs and the outputs.
2-58