VariableSettings

R2026b

Tunable parameter settings of fuzzy variables

Description

When tuning a fuzzy inference system using the tunefis function, use VariableSettings objects to specify tunable parameter settings for input and output variables.

Creation

Create a VariableSettings object using the getTunableSettings function. The first and second outputs of getTunableSettings contain VariableSettings objects for input and output variables, respectively.

Properties

FISName — Name of fuzzy inference system

Read-only: string

This property is read-only.

Name of fuzzy inference system, represented as a string.

Type — Type of variable

Read-only: "input" | "output"

This property is read-only.

Type of variable, represented as either "input" or "output" for input and output variables, respectively.

VariableName — Name of variable

Read-only: string

This property is read-only.

Name of variable, represented as a string.

MembershipFunctions — Membership function settings

MembershipFunctionSettings object | MembershipFunctionSettingsType2 object

Membership function settings, specified as one of these values:

• MembershipFunctionSettings object when the corresponding variable contains type-1 membership functions

• MembershipFunctionSettingsType2 object when the corresponding variable contains type-2 membership functions

Object Functions

setTunable

Set specified parameter settings as tunable or nontunable

Examples

Obtain Tunable Settings of Input and Output Variables from FIS

Create a fuzzy inference system.

fis1 = mamfis(Name="fis1",NumInputs=2,NumOutputs=1);

Obtain the tunable settings of input and output variables of the fuzzy inference system.

[in,out] = getTunableSettings(fis1);

You can use dot notation to specify the tunable settings of input and output variables.

For the first membership function of input 1, set the first and third parameters to tunable.

in(1).MembershipFunctions(1).Parameters.Free = [1 0 1];

For the first membership function of input 2, set the minimum parameter range to 0.

in(2).MembershipFunctions(1).Parameters.Minimum = 0;

For the first membership function of the output variable, set the maximum parameter range to 1.

out(1).MembershipFunctions(1).Parameters.Maximum = 1;

Obtain Tunable Settings of Input and Output Variables from Type-2 FIS

Create a type-2 fuzzy inference system.

fis = mamfistype2(Name="fis1",NumInputs=2,NumOutputs=1);

Obtain the tunable settings of the input and output variables of the fuzzy inference system.

[in,out] = getTunableSettings(fis);

You can use dot notation to specify the tunable settings of the membership functions of the input and output variables.

For the first membership function of input 1, set the first and third upper membership function parameters as tunable.

in(1).MembershipFunctions(1).UpperParameters.Free = [1 0 1];

For the first membership function of input 2, set the tunable range of the lower membership function scale to be between 0.7 and 0.9.

in(2).MembershipFunctions(1).LowerScale.Minimum = 0.7;
in(2).MembershipFunctions(1).LowerScale.Maximum = 0.9;

For the first membership function of output 1, set the tunable range of the lower membership function lag to be between 0.1 and 0.4.

in(2).MembershipFunctions(1).LowerLag.Minimum = 0.1;
in(2).MembershipFunctions(1).LowerLag.Maximum = 0.4;

By default, the tunable settings for a type-2 FIS produce symmetric lag results in the tuned system. To allow for asymmetric lag results, specify the AsymmetricLag name-value argument.

[in2,out2] = getTunableSettings(fis,AsymmetricLag=true);

Version History

Introduced in R2019a