Membership Trapezoid function Plot

How would I plot the membership Trapezoid function for the Last Hop based on the follwoing table please

Answer 1

[Ameri]

Thank you for your response, have you checked the table please.

[Ameri]

Thank you so much dear Sam.

[Sam Chak]

You are welcome, @Ameri. If the MATLAB code and explanation are helpful, would you accepting ✔ and voting 👍 my Answer? 😅

Answer 2

[Sam Chak]

Hi @Ameri

The range for Last Hop is not given. So, you might try something like this:

fis = mamfis;

% Option #1: using rectified linear MFs
fis = addInput(fis, [-1 +1], 'Name', 'LH1');
fis = addMF(fis, 'LH1', 'linzmf', [-0.25 0.25], 'Name', 'Bad');
fis = addMF(fis, 'LH1', 'linsmf', [-0.25 0.25], 'Name', 'Good');

% Option #2: using trapezoidal MFs
fis = addInput(fis, [-1 +1], 'Name', 'LH2');
fis = addMF(fis, 'LH2', 'trapmf', [-2 -1 -0.25 0.25], 'Name', 'Bad');
fis = addMF(fis, 'LH2', 'trapmf', [-0.25 0.25 +1 +2], 'Name', 'Good');

% Plots
figure(1)
subplot(2,1,1)
plotmf(fis, 'input', 1), grid on, title('Last Hop using rectified linear MFs')
subplot(2,1,2)
plotmf(fis, 'input', 2), grid on, title('Last Hop using trapezoidal MFs')

[Sam Chak]

Hi @Ameri,

Thanks for you reply. If the MATLAB code is helpful in plotting the membership functions (MFs), please consider accepting ✔ and voting 👍 the Answer. Thanks a bunch! 🙏

By the way, I have checked the table and it looks like the Fuzzy Rules because of the word "Decision".

Also, I used two MFs because there are "Yes" and "No", assuming that "Bo" was a typo. I should have used "Yes" and "No", instead of "Good" and "Bad".

Two types of MFs are demonstrated: one is a rectified linear function, and the other is a trapezoidal function which you described in your problem. Both give the same shapes within the defined range in the Universe of Discourse , though I preferred the first approach.

I made up this range . You should define it according to what you know about the Last Hop data. If it is some kind of questionaire with the scale , then 1 and 2 are No, 3 is Indecisive (half no/half yes), 4 and 5 are Yes.

fis = mamfis;

fis = addInput(fis, [1 5], 'Name', 'LH');
fis = addMF(fis, 'LH', 'linzmf', [2 4], 'Name', 'No');  % Z-shaped, [Hi_value, Lo_value]
fis = addMF(fis, 'LH', 'linsmf', [2 4], 'Name', 'Yes'); % S-shaped, [Lo_value, Hi_value]

plotmf(fis, 'input', 1), grid on, title('Last Hop')

[Ameri]

Thank you.