Module type2fuzzy.membership.zslicetype2fuzzyset

Classes

class ZSliceType2FuzzySet

datastructure defining a z-slice type-2 fuzzy set is a dictionary having an interval type-2 fuzzy set for every z_value such as: key: value of z-slice value: corresponding interval typ2-2 fuzzy set

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class ZSliceType2FuzzySet:

        def __init__(self):
                '''
                datastructure defining a z-slice type-2 fuzzy set is a dictionary having
                an interval type-2 fuzzy set for every z_value such as:
                key: value of z-slice
                value: corresponding interval typ2-2 fuzzy set
                '''
                self._z_slice_set_elements = {}
                self._empty = True

        @ classmethod
        def from_general_type2_set(cls, gt2fs, no_slices):
                
                zt2fs = cls()

                z_vals = np.linspace(0, 1, no_slices+1)

                for z_val in z_vals:
                        z_sliced_set =  gt2fs.z_slice(z_val)

                        if not z_sliced_set.empty:
                                zt2fs.add_element(z_val, z_sliced_set)# 
                                zt2fs._empty = False
                return zt2fs

        @property
        def empty(self):
                return self._empty

        def add_element(self, z_slice_val, z_sliced_set):
                self._z_slice_set_elements[z_slice_val] = z_sliced_set


        @staticmethod
        def adjust_value(val, val_array):
                val_array=np.array(val_array)
                idx = (np.abs(val_array - val)).argmin()
                return val_array[idx]

        def __getitem__(self, z_slice_val):
                '''
                For a given z-slice value, 
                return the corresponding interval type-2 fuzzy set

                Arguments:
                ----------
                z_slice_val -- value of z-slice

                Returns:
                --------
                it2fs - corresponding interval type-2 set
                '''
                if z_slice_val not in self.zslices():
                        raise Exception(f'z-slice value of {z_slice_val} not in this set.')

                z_slice_val = self.adjust_value(z_slice_val, self.zslices())

                return self._z_slice_set_elements[z_slice_val]

        def zslices(self):
                return list(self._z_slice_set_elements.keys())

        def __str__(self):
                '''

                '''
                representation = []

                for slice in self._z_slice_set_elements:
                        representation.append(f'slice {slice}:\n {self._z_slice_set_elements[slice]}')

                return '\n'.join(representation)
        
        def __repr__(self):
                return f'{self.__class__.__name__}(str(self))'

Static methods

def adjust_value(val, val_array)

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@staticmethod
def adjust_value(val, val_array):
        val_array=np.array(val_array)
        idx = (np.abs(val_array - val)).argmin()
        return val_array[idx]

def from_general_type2_set(gt2fs, no_slices)

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@ classmethod
def from_general_type2_set(cls, gt2fs, no_slices):
        
        zt2fs = cls()

        z_vals = np.linspace(0, 1, no_slices+1)

        for z_val in z_vals:
                z_sliced_set =  gt2fs.z_slice(z_val)

                if not z_sliced_set.empty:
                        zt2fs.add_element(z_val, z_sliced_set)# 
                        zt2fs._empty = False
        return zt2fs

Instance variables

var empty

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@property
def empty(self):
        return self._empty

Methods

def add_element(self, z_slice_val, z_sliced_set)

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def add_element(self, z_slice_val, z_sliced_set):
        self._z_slice_set_elements[z_slice_val] = z_sliced_set

def zslices(self)

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def zslices(self):
        return list(self._z_slice_set_elements.keys())