plotfiserr

Plot simulation error for fuzzy system compared to reference outputs

Since R2024b

Syntax

plotfiserr(fis,x,y)

plotfiserr(fis,x,y,Name=Value)

Description

plotfiserr(fis,x,y) simulates fuzzy inference system fis using the reference input values in x and visualizes the output error with respect to the reference outputs in y. For a FIS with multiple outputs, this syntax analyzes the error for the first output.

plotfiserr(fis,x,y,Name=Value) configures the simulation error plot using one or more name-value arguments.

Examples

View Error Distribution for Fuzzy Inference System

Load a Mamdani fuzzy inference system.

fisM = readfis("tipper");

Create a Sugeno version of the same fuzzy system.

fisS = convertToSugeno(fisM);

Create random reference input values.

x = 10*rand(100,2);

Compute reference output values using fisM.

y = evalfis(fisM,x);

Evaluate fisS and plot the error distribution with respect to the output from fisM.

plotfiserr(fisS,x,y)

The largest errors are in the following regions:

• High service rating and low food rating

• High food rating and low service rating

Input Arguments

fis — Fuzzy inference system

mamfis object | sugfis object | mamfistype2 object | sugfistype2 object | fistree object

Fuzzy inference system, specified as one of the following:

• mamfis object — Mamdani fuzzy inference system

• sugfis object — Sugeno fuzzy inference system

• mamfistype2 object — Type-2 Mamdani fuzzy inference system

• sugfistype2 object — Type-2 Sugeno fuzzy inference system

• fistree object — Tree of interconnected fuzzy inference systems

x — Reference input values

array

Reference input values, specified as an M-by-N_X array, where M is the number of reference data points and N_X is the number of inputs in fis.

y — Reference output values

array

Reference output values, specified as an M-by-N_Y array, where M is the number of reference data points and N_Y is the number of outputs in fis.

Name-Value Arguments

Specify optional pairs of arguments as Name1=Value1,...,NameN=ValueN, where Name is the argument name and Value is the corresponding value. Name-value arguments must appear after other arguments, but the order of the pairs does not matter.

Example: SelectedOutput=2 selects the second FIS output for analysis.

SelectedOutput — Output variable to analyze

1 (default) | positive integer

Output variable to analyze, specified as a positive integer less than or equal to the number of outputs in fis.

NumSamplePoints — Number of sample points for output defuzzification

101 (default) | integer greater than 1

Number of sample points for output defuzzification when , specified as an integer greater than 1.

Dependencies

plotfiserr ignores this property when evaluating a Sugeno FIS.

Alternative Functionality

App

You can interactively view FIS simulation errors using the Fuzzy Logic Designer app. For more information, see Analyze Fuzzy System Using Fuzzy Logic Designer.

Version History

Introduced in R2024b