comparefis

Plot simulated output of fuzzy systems for comparison

Since R2024b

Syntax

comparefis(fis,x)

comparefis(fis,x,Name=Value)

Description

comparefis(fis,x) evaluates each fuzzy inference system (FIS) in fis using the input value sin x and shows the simulated output values in a stacked plot.

comparefis(fis,x,Name=Value) configures the comparison plot using one or more name-value arguments.

Examples

Compare FIS Outputs

Load a Mamdani fuzzy inference system.

fisM = readfis("tipper");

Create a Sugeno version of the same fuzzy system.

fisS = convertToSugeno(fisM);
fisS.Name = "tipperSugeno";

Create random reference input values.

x = 10*rand(100,2);

Compare the outputs of the two fuzzy systems.

comparefis([fisM fisS],x)

The output of the Sugeno system closely matches the output of the Mamdani system.

Compare FIS Outputs to Reference Data

Evaluate tuned FIS performance from Tune Fuzzy Inference System at the Command Line.

Load the training data and extract a set of validation data.

[data,name] = loadGasData;
X = data(:,1:6);
Y = data(:,7);
vldX = X(2:2:end,:);
vldY = Y(2:2:end,:);

Load the trained FIS objects, including an intermediate FIS with learned rules and a final FIS with tuned membership function parameters.

tunedfis = load("tunedfismpgprediction.mat");
fisLearnedRules = tunedfis.fisout1;
fisLearnedRules.Name = "LearnedRules";
fisTunedMFs = tunedfis.fisout;
fisTunedMFs.Name = "TunedMFs";

Evaluate the FIS objects and compare their outputs to the validation data.

fis = [fisLearnedRules, fisTunedMFs];
comparefis(fis,vldX,OutputData=vldY)

View the error plot and root-mean-squared-error (RMSE) for both FIS objects.

comparefis(fis,vldX, ...
    OutputData=vldY, ...
    ShowError=true)

Input Arguments

fis — Fuzzy inference systems

array of fuzzy inference system objects | mamfis object | sugfis object | mamfistype2 object | sugfistype2 object | fistree object

Fuzzy inference systems to evaluate, specified as one of the following FIS objects or an array of such objects. All the FIS object must have the same number of inputs and outputs and each FIS object must have a unique name.

• 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.

If you specify a fistree object in fis, all the fuzzy systems in fis must be fistree objects.

x — Input values

array

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.

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: MergeInputs=false plots each input variable in its own axes.

OutputData — Reference output values

[] (default) | 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.

ShowLegend — Option to show plot legend

true (default) | false

Option to display the plot legend, specified as a logical value.

• true — Display the legend.

• false — Do not display the legend.

ShowError — Option to plot the output error

false (default) | true

Option to plot the output error, specified as a logical value.

• true — Plot the output error.

• false — Do not plot the output error.

MergeInputs — Option to plot all inputs on the same axes

true (default) | false

Option to plot all inputs on the same axes, specified as a logical value.

• true — Plot all inputs on the same axes.

• false — Plot each input in a separate axes.

MergeOutputs — Option to plot all outputs on the same axes

true (default) | false

Option to plot all outputs on the same axes, specified as a logical value.

• true — Plot all outputs on the same axes.

• false — Plot each output in a separate axes.

MergeErrors — Option to plot all errors on the same axes

true (default) | false

Option to plot all errors on the same axes, specified as a logical value.

• true — Plot all errors on the same axes.

• false — Plot each error in a separate axes.

SelectedInputs — Input variables to plot

"all" (default) | vector of positive indices | []

Input variables to plot, specified as a vector of positive indices. To plot all input variables, set SelectedInputs to "all". To suppress the input-signal plot, set SelectedInputs to "[]".

SelectedOutputs — Output variables to plot

"all" (default) | vector of positive indices

Output variables to plot, specified as a vector of positive indices. To plot all output variables, set SelectedOutputs to "all".

SelectedFIS — FISs simulation results to plot

"all" (default) | vector of positive indices

FISs to plot, specified as a vector of positive indices. To plot the simulation results for all FISs, set SelectedFIS to "all".

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

comparefis ignores this property when evaluating a Sugeno FIS.

Alternative Functionality

App

You can interactively compare FIS outputs using the Fuzzy Logic Designer app. For more information, see Analyze Fuzzy System Using Fuzzy Logic Designer.

Version History

Introduced in R2024b