Module type2fuzzy.type_reduction.it2_karnikmendel_reducer

import logging
from type2fuzzy.membership.crispset import CrispSet
from type2fuzzy.membership.intervaltype2fuzzyset import IntervalType2FuzzySet


def it2_kernikmendel_reduce(it2fs, precision=5, information='none'):
        reduced_set = None

        if information == 'none':
                reduced_set = _it2_kernikmendel_reduce_noinfo(it2fs, precision)
        elif information == 'full':
                reduced_set = _it2_kernikmendel_reduce_fullinfo(it2fs, precision)
        
        return reduced_set

def _it2_kernikmendel_reduce_noinfo(it2fs, precision=5):

        numerator = 0
        denominator = 0
        error_threshold = 1e-5
        counter = 0
        primary_domain_elements = it2fs.primary_domain()

        centroid = CrispSet(primary_domain_elements[0], primary_domain_elements[len(primary_domain_elements)-1])


        centroid_left = it2fs.mid_domain_element()
        while True:

                centroid.left = centroid_left
                numerator = 0
                denominator = 0

                for domain_element in it2fs.primary_domain():

                        if domain_element >= centroid_left:
                                numerator = numerator + (domain_element * it2fs[domain_element].left)
                                denominator = denominator + it2fs[domain_element].left
                        else:
                                numerator = numerator + (domain_element * it2fs[domain_element].right)
                                denominator = denominator + it2fs[domain_element].right

                if denominator == 0:
                        centroid.left = it2fs.mid_domain_element()
                        logging.log(logging.ERROR, 'error in calculating z_l, denominator is 0')
                        break

                centroid_left = numerator / denominator

                if abs(centroid_left - centroid.left) <= error_threshold:
                        break
                
                if counter == 15:
                        break

                counter = counter + 1

        counter = 0
        centroid_right = it2fs.mid_domain_element()
        
        while True:

                centroid.right = centroid_right
                numerator = 0
                denominator = 0

                for domain_element in it2fs.primary_domain():

                        if domain_element <= centroid_right:
                                numerator = numerator + (domain_element * it2fs[domain_element].left)
                                denominator = denominator + it2fs[domain_element].left
                        else:
                                numerator = numerator + (domain_element * it2fs[domain_element].right)
                                denominator = denominator + it2fs[domain_element].right

                if denominator == 0:
                        centroid_right = it2fs.mid_domain_element()
                        logging.log(logging.ERROR, 'error in calculating z_l, denominator is 0')
                        break

                centroid_right = numerator / denominator

                if abs(centroid_right - centroid.right) <= error_threshold:
                        break
                
                if counter == 15:
                        break

                counter = counter + 1

        centroid.left = round(centroid.left, precision)
        centroid.right = round(centroid.right, precision)
        return centroid


def _it2_kernikmendel_reduce_fullinfo(it2fs, precision=5):

        numerator = 0
        denominator = 0
        error_threshold = 1e-5
        counter = 0
        primary_domain_elements = it2fs.primary_domain()

        centroid = CrispSet(primary_domain_elements[0], primary_domain_elements[len(primary_domain_elements)-1])

        logging.log(logging.INFO,'starting recursion...')

        centroid_left = it2fs.mid_domain_element()
        logging.log(logging.DEBUG, f'Initial value of centroid left= {centroid_left}')
        
        while True:

                centroid.left = centroid_left
                numerator = 0
                denominator = 0

                for domain_element in it2fs.primary_domain():

                        if domain_element >= centroid_left:
                                numerator = numerator + (domain_element * it2fs[domain_element].left)
                                denominator = denominator + it2fs[domain_element].left
                        else:
                                numerator = numerator + (domain_element * it2fs[domain_element].right)
                                denominator = denominator + it2fs[domain_element].right

                logging.log(logging.DEBUG, f'numerator: {numerator}, denominator: {denominator}, centroid: {centroid_left}')

                if denominator == 0:
                        centroid.left = it2fs.mid_domain_element()
                        logging.log(logging.ERROR, 'error in calculating z_l, denominator is 0')
                        break

                centroid_left = numerator / denominator

                if abs(centroid_left - centroid.left) <= error_threshold:
                        break
                
                if counter == 15:
                        logging.log(logging.ERROR, 'cannot converge...')
                        break

                counter = counter + 1

        counter = 0
        centroid_right = it2fs.mid_domain_element()
        logging.log(logging.DEBUG,f'Initial value of centroid right= {centroid_right}')
        
        while True:

                centroid.right = centroid_right
                numerator = 0
                denominator = 0

                for domain_element in it2fs.primary_domain():

                        if domain_element <= centroid_right:
                                numerator = numerator + (domain_element * it2fs[domain_element].left)
                                denominator = denominator + it2fs[domain_element].left
                        else:
                                numerator = numerator + (domain_element * it2fs[domain_element].right)
                                denominator = denominator + it2fs[domain_element].right

                if denominator == 0:
                        centroid_right = it2fs.mid_domain_element()
                        logging.log(logging.ERROR, 'error in calculating z_l, denominator is 0')
                        break

                centroid_right = numerator / denominator

                logging.log(logging.DEBUG, f'numerator: {numerator}, denominator: {denominator}, centroid: {centroid_right}')

                if abs(centroid_right - centroid.right) <= error_threshold:
                        break
                
                if counter == 15:
                        break

                counter = counter + 1

        return centroid