Module type2fuzzy.type1_defuzzification.cog_defuzzifier

Functions

def cog_defuzzify(type1_set)

Centre of gravity defuzzification method

References:

Pedrycz, Witold. Fuzzy control and fuzzy systems (2nd. Research Studies Press Ltd., 1993.

Arguments:

type1_set – Type1FuzzySet, the set whose centroid is to be computed

Returns:

centroid – float, the centroid of this set

Raises:

Exception if the denominator of the calculation is zero

Expand source code

def cog_defuzzify(type1_set):
        '''
        Centre of gravity defuzzification method

        References:
        -----------
        Pedrycz, Witold. Fuzzy control and fuzzy systems (2nd. Research Studies Press Ltd., 1993.

        Arguments:
        ----------
        type1_set   -- Type1FuzzySet, the set whose centroid is to be computed

        Returns:
        --------
        centroid    -- float, the centroid of this set

        Raises:
        -------
        Exception if the denominator of the calculation is zero

        '''
        numerator = 0
        denominator = 0

        for domain_element in type1_set.domain_elements():
                numerator = numerator + (domain_element * type1_set[domain_element])
                denominator = denominator + type1_set[domain_element]

        centroid = 0
        if denominator == 0:
                raise Exception('Cannot determine centroid')
        else:
                centroid = numerator / denominator

        return centroid