Defuzzification's method with Sugeno

I am generating a fuzzy inference system structure with the sugeno's method. I have succeed of producing an answer which show me : csqSFTxt = [(SF.output.mf(i).name ; num2str(csqSF(i))], but I don't know how to attribuate a value to the SF.output.mf(i).name in order to estimate the average of the complete answer. For example if I can say "low" = 2 , "medium"=4 and "high"=6, with the output: output = [(low; 0.2), (medium; 0.3), (high; 0.6)] output= (2*0.2+4*0.3+6*0.6)/(0.2+0.3+0.6)

I can't find example in the help's menu of matlab. Thank you by advance for the answers.