Nonsingleton input - A Fuzzy logic problem

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Emanuel
Emanuel on 5 Dec 2012
Hi, i'm a new student of Fuzzy theory, and i'm trying to resolve the following Mamdani problem, considering that the input are nonsigleton.
I have 2 inputs: Temperature (low, medium, high) and price (low, medium, high), that are built using Gaussian and triangular functions, respectively:
%temperature
temperature=15:0.1:45;
tlow = gaussmf(temperature, [2.1 15]);%
tmedium = gaussmf(temperature, [2.1 24]);
thigh = gaussmf(temperature, [2.1 36.5]);
%price
price=1:0.1:6;
plow = trimf(price, [-0.3 1 2.4]);
pmedium = trimf(price, [1.7 3 4.3]);
phigh = trimf(price, [3.7 6 8.3]);
The output function of the problem is the soda consumption (low, medium, high), and is a triangular function:
consumption=500:0.1:6000;
clow = trimf(consumption, [-1000 500 2000]);
cmedium = trimf(consumption, [1500 3000 4500]);
chigh = trimf(consumption, [4000 6000 8000]);
Rules:
1) if TEMPERATURE is low and PRICE is low then CONSUMPTION is big;
2) if TEMPERATURE is low and PRICE is medium then CONSUMPTION is medium;
3) if TEMPERATURE is low and PRICE is high then CONSUMPTION is small;
4) if TEMPERATURE is medium and PRICE is low then CONSUMPTION is big;
5) if TEMPERATURE is medium and PRICE is medium then CONSUMPTION is medium;
6) if TEMPERATURE is medium and PRICE is high then CONSUMPTION is small;
7) if TEMPERATURE is high and PRICE is low then CONSUMPTION is big;
8) if TEMPERATURE is high and PRICE is medium then CONSUMPTION is medium;
9) if TEMPERATURE is high and PRICE is high then CONSUMPTION is small.
I know that first it is necessary calculate the firing level, but i don't know how. Somebody can help me with this problem?
  2 Comments
Emanuel
Emanuel on 6 Dec 2012
Edited: Emanuel on 6 Dec 2012
price is high. Could you see my program?
% OPERADOR MAMDANI
clear all
clc
close all
%1ª entrada - Temperatura
t=15:0.1:45;
tbaixa = gaussmf(t, [2.1 15]);%gaussiana = A
tmedia = gaussmf(t, [2.1 24]);%gaussiana = A
talta = gaussmf(t, [2.1 36.5]);%gaussiana = A
plot(t,tbaixa,'b')
hold
plot(t,tmedia,'r')
plot(t,talta,'g')
legend('tbaixa','tmedia','talta')
%1ª entrada - F1 - Temperatura
t=18:0.1:48;
tbaixan = gaussmf(t, [2.2 18]);%gaussiana = A
tmedian = gaussmf(t, [2.2 27]);%gaussiana = A
taltan = gaussmf(t, [2.2 39.5]);%gaussiana = A
figure
plot(t,tbaixan,'b')
hold
plot(t,tmedian,'r')
plot(t,taltan,'g')
legend('tbaixa','tmedia','talta')
tfiringb=min(tbaixa,tbaixan);
tfiringb=max(tfiringb);%firing level
tfiringm=min(tmedia,tmedian);
tfiringm=max(tfiringm);%firing level
tfiringa=min(talta,taltan);
tfiringa=max(tfiringa);%firing level
%2ª entrada - Preço
pr=1:0.1:6;
pbaixo = trimf(pr, [-0.3 1 2.4]);%triangular=B
pmedio = trimf(pr, [1.7 3 4.3]);%triangular=B
palto = trimf(pr, [3.7 6 8.3]);%triangular=B
figure
plot(pr,pbaixo,'b')
hold
plot(pr,pmedio,'r')
plot(pr,palto,'g')
legend('pbaixo','pmedio','palto')
%2ª entrada -F2- Preço
pr=0:0.1:5;
pbaixon = trimf(pr, [-0.1 0.8 2]);%
pmedion = trimf(pr, [1.9 3.3 4.7]);%triangular=B
palton = trimf(pr, [3.2 5.6 8]);%triangular=B
figure
plot(pr,pbaixon,'b')
hold
plot(pr,pmedion,'r')
plot(pr,palton,'g')
legend('pbaixo','pmedio','palto')
%Achando o ponto
pfiringb=min(pbaixo,pbaixon);
pfiringb=max(pfiringb);%firing level
pfiringm=min(pmedio,pmedion);
pfiringm=max(pfiringm);%firing level
pfiringa=min(palton,palton);
pfiringa=max(pfiringa);%firing level
%Saída - Consumo
consumo=500:0.1:6000;
cbaixo = trimf(consumo, [-1000 500 2000]);%
cmedio = trimf(consumo, [1500 3000 4500]);%
calto = trimf(consumo, [4000 6000 8000]);%
figure
plot(consumo,cbaixo,'b')
hold
plot(consumo,cmedio,'r')
plot(consumo,calto,'g')
legend('cbaixo','cmedio','calto')
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
A1=min(tfiringb,pfiringb);%firing level para 1ª regra
con1=combvec(calto,A1);%
con1=min(con1);
plot(con1)
A2=min(tfiringb,pfiringm);%firing level para 2ª regra
con2=combvec(cmedio,A2);
con2=min(con2);
A3=min(tfiringb,pfiringa);%firing level para 3ª regra
con3=combvec(cbaixo,A2);
con3=min(con3);
A4=min(tfiringm,pfiringb);%firing level para 4ª regra
con4=combvec(calto,A4);
con4=min(con4);
A5=min(tfiringm,pfiringm);%firing level para 5ª regra
con5=combvec(cmedio,A5);
con5=min(con5);
A6=min(tfiringm,pfiringa);%firing level para 6ª regra
con6=combvec(cbaixo,A6);
con6=min(con6);
A7=min(tfiringa,pfiringb);%firing level para 7ª regra
con7=combvec(calto,A7);
con7=min(con7);
A8=min(tfiringa,pfiringm);%firing level para 8ª regra
con8=combvec(cmedio,A8);
con8=min(con8);
A9=min(tfiringa,pfiringa);%firing level par 9ª regra
con9=combvec(cbaixo,A9);
con9=min(con9);
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

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