defuzz

Defuzzify membership function

Syntax

output = defuzz(x,mf,method)

Description

output = defuzz(x,mf,method) returns the defuzzified output value for membership function mf at the variable values in x using the specified defuzzification method.

Examples

Obtain Defuzzified Value

x = -10:0.1:10;
mf = trapmf(x,[-10 -8 -4 7]);
out = defuzz(x,mf,'centroid')

out = -3.2857

Input Arguments

x — Variable values

vector

Variable values, specified as a vector.

mf — Membership function values

vector

Membership function values, specified as a vector with the same length as x. Each element of mf contains a fuzzy membership value for the corresponding variable value in x.

method — Defuzzification method

'centroid' | 'bisector' | 'mom' | 'lom' | 'som' | character vector | string

Defuzzification method, specified as one of the following:

• 'centroid' — Centroid of the area under the output fuzzy set

• 'bisector' — Bisector of the area under the output fuzzy set

• 'mom' — Mean of the values for which the output fuzzy set is maximum

• 'lom' — Largest value for which the output fuzzy set is maximum

• 'som' — Smallest value for which the output fuzzy set is maximum

• Character vector or string that contains the name of a custom function in the current working folder or on the MATLAB^® path

For more information on:

• The built-in defuzzification methods, see Defuzzification Methods.

• Custom defuzzification methods, see Build Fuzzy Systems Using Custom Functions

Output Arguments

output — Defuzzified output value

scalar

Defuzzified output value, returned as a scalar.

Version History

Introduced before R2006a