I use fuzzylite to implement a fuzzy system. I have three inputs and 1 output. For some inputs’ values, I obtain nan as an output ( I verified that all the input values are all in the predefined ranges). And I define all the possible combination of rules ( 81 rules).
I use mandani for the fuzzy inference system and I set centroid as a deffuzifier.
What are the possible reasons to obtain nan as output?