What is the fourth array element denotes (specified as NaN in code below) in the input to fcm function of matlab 2019?

c = 3;
m = 2.0;
iter = 20;
minImp = 0.00001;
[centers U] = fcm(data,c,[m,iter,minImp,NaN])

[NALLARASU KRISH]

The fourth element is nothing but Obj Fun display option. Its default value is 1 (to display) the Obj Fun values for each iteration. If the fourth element is given 0 (false), then the Obj Fun values will not be displayed.

Answer 1

[Dyuman Joshi]

From the documentation of fcm(), for the syntax [centers,U] = fcm(data,Nc,options) - "If any element of options is NaN, the default value for that option is used."

Here are documentation of fcm() highlighting the options input argument (you can check the default values here) -

R2019a - https://in.mathworks.com/help/releases/R2019a/fuzzy/fcm.html?s_tid=doc_ta#buv_wo_-Nc

R2019b - https://in.mathworks.com/help/releases/R2019b/fuzzy/fcm.html?s_tid=doc_ta#buv_wo_-Nc

[NALLARASU KRISH]

Thank you for providing 2019a documentation that clarified my doubt.

[Dyuman Joshi]

You're welcome!