How to create output Surface for fuzzy defuzzificaion method?

I have developed new method of fuzzy defuzzification. How to generate output surface for the proposed method? I want to comparison of proposed method with existing methods SOM, LOM, MOM, centroid and bisector in the form of output surface.

e.g.

gensurf(fis)

gensurf(fis,options)

or

surfview(fis)

In these methods, no option to select defuzzification method. Only inputs and output can be set. How to plot surface for different defuzzificztion methods?

Any other method for comparison? How to compute performance index for defuzzication method?

Please guide me.

[Sam Chak]

Good to hear that a new defuzzification method is developed. To make the comparison meaningful, you must choose and compute the performance index for each method and to determine the method that delivers the best result in certain circumstances.

Answer 1

[Sam Chak]

Hi kalpana,

If you want to create a Custom Defuzzification Function, then read the information on this link:

https://www.mathworks.com/help/fuzzy/building-fuzzy-inference-systems-using-custom-functions.html#brkii8c-3

[kalpana]

Thank you sir, I already created defuzzification function. I want to analyze it and compare with existing methods. Is there any way for comparison? Also, how to generate output surface for the proposed method?

[Sam Chak]

1. Comparing defuzzification methods is subjective, depending on the aspects of comparison. The best is to compare them in your field of expertise, because I don't know what your fuzzy systems are used for.
2. Are you able to use gensurf(fis)?

[kalpana]

I have used gensurf(fis) , it has parameters for two inputs and one output. No option to select defuzzification method. Even if defuz method is changed, showing same surface.

gensurf(fis)

gensurf(fis,options)

[X,Y,Z] = gensurf(___)

[Sam Chak]

Please check the type of your fuzzy system. Is it Mamdani or Sugeno? For your info, custom defuzzification functions are not supported for Sugeno-type systems.

[kalpana]

Sir, my fuzzy system is Mamdani

[Sam Chak]

Can you generate the surface in the Fuzzy Logic Designer app?

https://www.mathworks.com/help/fuzzy/surfview.html

What command did you use to integrate the Custom defuzzification function into the FIS when generating the Mamdani fuzzy inference system?

https://www.mathworks.com/help/fuzzy/mamfis.html