How to get an output value for a Mamdani fuzzy system using evalfis() command

How I can get the output value for mamdani fuzzy system using this command evalfis([1 2],fis).

FIS Evaluation: To evaluate the output of a fuzzy system for a given input combination, use the evalfis command. For example, evaluate a using input variable values of 1 and 2. evalfis([1 2],fis) ans = 5.5586 You can also evaluate multiple inputs.

Answer 1

[Sam Chak]

It is likely simpler than you have anticipated if you design the Mamdani system correctly according to mathematical reasoning procedure.

%% Design a Mamdani fuzzy system called "fis"
fis = mamfis;

% Fuzzy Input 1
fis = addInput(fis,  [0 2], 'Name', 'in1');
fis = addMF(fis, 'in1', 'trimf', [0  1  2], 'Name', 'All-Encompassing');

% Fuzzy Input 2
fis = addInput(fis,  [1 3], 'Name', 'in2');
fis = addMF(fis, 'in2', 'trimf', [1  2  3], 'Name', 'All-Encompassing');

% Fuzzy Output 1
fis = addOutput(fis, [3 8], 'Name', 'out');
val = 5.5586;       % desired value
fis = addMF(fis, 'out', 'trimf', [val-2 val val+2], 'Name', 'myValue');

% Fuzzy Rule
fis = addRule(fis, "If in1 is All-Encompassing and in2 is All-Encompassing then out is myValue");

%% Testing evalfis output
input1 = 1;
input2 = 2;
output = evalfis(fis, [input1, input2])

output = 5.5586

plotrule(fis, Inputs=[1, 2])