Built-in Fuzzy Sets

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Forthcoming Releases:

Fuzzy Logic:

Neural Net:
Release of NXL3


Built-in Fuzzy Sets

Fuzzy sets are one of the 3 components of our FL controllers, along with the Variable Set and the Rule Set.  The controller being constructed with a given shape (3x3 or 5x5), fuzzy sets will obviously have to conform the type of FL controller being built.

Again, in order to keep sFLC3 simple to use, a number of predefined fuzzy sets have been built in and can therefore be called and modified with just one or 2 API calls (see sample code for more details).

Lastly, the semantics behind variables has not been ignored and has also been kept simple by attaching a given set of "labels" to each of our fuzzy states.  Labels can be changed like anything else.

const string strStates5[3][5] =

"Very Low"
, "Low", "Med", "High", "Very High",
"Very Neg.", "Neg.", "Null", "Pos.", "Very Pos.",
"Very Small", "Small", "Avg.", "Big", "Very Big"

const string strStates3[3][3] =

"Low", "Med", "High",
"Neg.", "Null", "Pos.",
"Small", "Avg.", "Big"


"3x3 Shape"

The 3x3 Shape means that the 2 variables will both use a 3-state fuzzy set (such as "Low", "Medium", and "High").  The sFLC3 API includes 9 predefined fuzzy set models to facilitate the building of fuzzy logic controllers:


To better comprehend what is behind those names, a spreadsheet here describes and displays the different shapes: FS3.XLS or FS3.MHT

Nota Bene 1: All fuzzy sets are normalised to the [-1:+1] range, meaning -1 is the 'absolute' definition of "Very Low" or "Very Small", and +1 is obviously the opposite "Very High" or "Very Big". Secondly, a variable associated to a fuzzy set will be given a 'degree of membership' for each Fuzzy State in the associated Fuzzy Set. That degree of memebership is measured from 0 to 1 or 0% (not attributable to that state) to 100% (fully attributable to that state).

Nota Bene 2: Users are limited to predefined Fuzzy Set Models and can also create their own custom fuzzy sets.


"5x5 Shape"

Again, this means that both variables will use a 5-state fuzzy set.  The sFLC3 API here includes 5 predefined fuzzy sets:


And here again, we have a spreadsheet available in 2 different formats to describe the shape and behaviour of those fuzzy sets: FS5.XLS and FS5.MHT






Home Up Fuzzy Set Model 0 (3x3) Fuzzy Set Model 1 (3x3) Fuzzy Set Model 2 (3x3) Fuzzy Set Model 3 (3x3) Fuzzy Set Model 4 (3x3) Fuzzy Set Model 5 (3x3) Fuzzy Set Model 6 (3x3) Fuzzy Set Model 7 (3x3) Fuzzy Set Model 8 (3x3) Fuzzy Set Model 0 (5x5) Fuzzy Set Model 1 (5x5) Fuzzy Set Model 2 (5x5) Fuzzy Set Model 3 (5x5) Fuzzy Set Model 4 (5x5) Best viewed with MS Internet Explorer 5 and above

Page last modified: May 08, 2008
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