Click the Add Input Variable, Add Output Variable, Edit Input Variable, or Edit Output Variable button on the Variables page of the Fuzzy System Designer to display this dialog box.
Use this dialog box to modify the linguistic variables in a fuzzy system.
This dialog box includes the following components:
Name—Specifies the name of the linguistic variable.
Range—Specifies the range of the linguistic variable.
minimum—Specifies the minimum value of the linguistic variable.
maximum—Specifies the maximum value of the linguistic variable.
Membership functions—Specifies the linguistic terms for the linguistic variable and the degree of membership of the linguistic variable within those linguistic terms. Each element of the Membership functions array corresponds to a linguistic term.
Name—Specifies the name of the membership function, or linguistic term, for the linguistic variable.
Shape—Specifies the type of function that determines the degrees of membership for the linguistic variable within the linguistic term Name. You can select the following functions:
Triangle—Specifies that a triangle function determines the degrees of membership for the linguistic variable.
Trapezoid—Specifies that a trapezoid function determines the degrees of membership for the linguistic variable.
Singleton—Specifies that a singleton function determines the degrees of membership for the linguistic variable. A singleton function has only one value. Therefore, no value of the linguistic variable has partial membership within the corresponding linguistic term.
Sigmoid—Specifies that a sigmoid function determines the degrees of membership for the linguistic variable.
Gaussian—Specifies that a Gaussian function determines the degrees of membership for the linguistic variable.
User-Defined—Specifies that a user-defined shape determines the degrees of membership for the linguistic variable. Use the Fuzzy Logic VIs to create or modify user-defined membership functions. Do not create or modify user-defined membership functions in the Edit Variable dialog box.
Color—Specifies the color of the membership function on the Membership functions graph.
Points—Specifies the base and top points of the membership function in order from left to right and base to top. The degree of membership of the linguistic variable within the linguistic term Name is 0 at the base points and 1 at the top points. Specify one point for a singleton function, three points for a triangle function, and four points for trapezoid, sigmoid, or Gaussian functions.
Add Membership Function—Creates a new membership function for the linguistic variable.
Delete Membership Function—Deletes the membership function currently visible in the Membership functions array.
Previous Membership Function—Displays the previous membership function in the Membership functions array.
Next Membership Function—Displays the next membership function in the Membership functions array.
Membership functions graph—Plots the membership functions for the linguistic variable.