MATLAB: Fuzzy parameters in Fuzzy Interface Structure

fuzzyFuzzy Logic Toolbox

Hi everyone…Is there someone who can guide me about fuzzy parameters..I have uploaded the image having Fuzzy Interface Structure at http://tinypic.com/view.php?pic=fcpgn6&s=6

what the field 'params' is showing and what the three values [-6.667 -5 -3.333] are depicting. Any help would be highly appreciated.

Best Answer

Yes, and use centroid deffuzzification method to compute output. You can change the 'and', 'OR' ,... methods in FIS Properties from Edit menu.

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MATLAB: Error with Fuzzy Tree Model

There were a couple of issues that needed fixing.

Every FIS needs to have its Inputs, Outputs and MFs defined separately.
FIS3 would not have two MFs at its inputs. All it gets from FIS1 or FIS2 is a number. It decides what that number means based on the MF defined on its (FIS3's) inputs. So, yes, in your case you would have to redefine FIS1 and FIS2 output MFs as the MFs for the two inputs to FIS3.
The error that you see - “Error using FuzzyInferenceSystem/addRule (line 1148). Invalid input membership function name in rule description.” is because the inputs of FIS3 are instantiated, by default, to have 3 MFs called 'mf1', 'mf2', 'mf3' for both the inputs. You can see this by typing the following in the command window after executing the script until the line that errors out:

fis3.Inputs(1).MembershipFunctions
fis3.Inputs(2).MembershipFunctions

They have these default member functions because fis3 was created in your script with the following command:

fis3 = mamfis('Name','fis3','NumInputs',2,'NumOutputs',1);

Here's the code with a couple of changes. You should be able to adapt this for your use:

% Fuzzy model 1
fis1 = mamfis('Name',"tipper1");
fis1 = addInput(fis1,[0 10],'Name',"service");
fis1 = addMF(fis1,"service","gaussmf",[1.5 0],'Name',"poor");
fis1 = addMF(fis1,"service","gaussmf",[1.5 5],'Name',"good");
fis1 = addMF(fis1,"service","gaussmf",[1.5 10],'Name',"excellent");
fis1 = addInput(fis1,[0 10],'Name',"food");
fis1 = addMF(fis1,"food","trapmf",[-2 0 1 3],'Name',"rancid");
fis1 = addMF(fis1,"food","trapmf",[7 9 10 12],'Name',"delicious");
fis1 = addOutput(fis1,[0 30],'Name',"tip1");
fis1 = addMF(fis1,"tip1","trimf",[0 5 10],'Name',"cheap");
fis1 = addMF(fis1,"tip1","trimf",[10 15 20],'Name',"average");
fis1 = addMF(fis1,"tip1","trimf",[20 25 30],'Name',"generous");
rulefis1a = "service==poor | food==rancid => tip1=cheap";
rulefis1b = "service==good => tip1=average";
rulefis1c = "service==excellent | food==delicious => tip1=generous";
rulefis1d = [rulefis1a rulefis1b rulefis1c];
fis1b = addRule(fis1,rulefis1d);
 
%Fuzzy model 2
fis2 = mamfis('Name',"tipper2");
fis2 = addInput(fis2,[0 10],'Name',"service");
fis2 = addMF(fis2,"service","gaussmf",[1.5 0],'Name',"poor");
fis2 = addMF(fis2,"service","gaussmf",[1.5 5],'Name',"good");
fis2 = addMF(fis2,"service","gaussmf",[1.5 10],'Name',"excellent");
fis2 = addInput(fis2,[0 10],'Name',"food");
fis2 = addMF(fis2,"food","trapmf",[-2 0 1 3],'Name',"rancid");
fis2 = addMF(fis2,"food","trapmf",[7 9 10 12],'Name',"delicious");
fis2 = addOutput(fis2,[0 30],'Name',"tip2");
fis2 = addMF(fis2,"tip2","trimf",[0 5 10],'Name',"cheap");
fis2 = addMF(fis2,"tip2","trimf",[10 15 20],'Name',"average");
fis2 = addMF(fis2,"tip2","trimf",[20 25 30],'Name',"generous");
rulefis2a = "service==poor | food==rancid => tip2=cheap";
rulefis2b = "service==good => tip2=average";
rulefis2c = "service==excellent | food==delicious => tip2=generous";
rulefis2d = [rulefis2a rulefis2b rulefis2c];
fis2b = addRule(fis2,rulefis2d);
%Fuzzy model 3
fis3 = mamfis('Name','fis3');
fis3 = addInput(fis3,[0 30],'Name',"tip1");
fis3 = addMF(fis3,"tip1","trimf",[0 5 10],'Name',"cheap");
fis3 = addMF(fis3,"tip1","trimf",[10 15 20],'Name',"average");
fis3 = addMF(fis3,"tip1","trimf",[20 25 30],'Name',"generous");
fis3 = addInput(fis3,[0 30],'Name',"tip2");
fis3 = addMF(fis3,"tip2","trimf",[0 5 10],'Name',"cheap");
fis3 = addMF(fis3,"tip2","trimf",[10 15 20],'Name',"average");
fis3 = addMF(fis3,"tip2","trimf",[20 25 30],'Name',"generous");
fis3.Outputs(1).Name = "final_tip";
fis3 = addMF(fis3,"final_tip","trapmf",[-2 0 1 3],'Name',"low");
fis3 = addMF(fis3,"final_tip","trapmf",[7 9 10 12],'Name',"high");
rulefis3a = "tip1==cheap | tip2==average => final_tip=low";
rulefis3b = "tip1==average => final_tip=low";
rulefis3c = "tip1==generous | tip2==generous => final_tip=high";
rulefis3d = [rulefis3a rulefis3b rulefis3c];
fis3b = addRule(fis3,rulefis3d);
con1 = ["tipper1/tip1" "fis3/tip1"];
con2 = ["tipper2/tip2" "fis3/tip2"];
aggTree = fistree([fis1b fis2b fis3],[con1;con2]);
aggTree.FIS(3) = addRule(aggTree.FIS(3), rulefis3d)
output = evalfis(aggTree,[0.2 0.25 0.3 0.2])

MATLAB: Does the ADDMF function implement a different set of rules in the Fuzzy Logic Toolbox 2.1.1 (R12.1) than in version 2.1 (R12)

This problem has been fixed in the Fuzzy Logic Toolbox 2.1.2 (R13).

If you are using a previous version, please see the workaround below:

As a suggested work-around, execute your code within MATLAB 6.1 and within the Fuzzy GUI that opens, go to Edit -> Rules. This will provide you with a GUI window in which you can use the CHANGE RULE button, after altering rules listed in the activation window to the actual implementation. This will correct the rules and surface appearance.

Best Answer

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MATLAB: Error with Fuzzy Tree Model

MATLAB: Does the ADDMF function implement a different set of rules in the Fuzzy Logic Toolbox 2.1.1 (R12.1) than in version 2.1 (R12)

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