Source code for pyFTS.partitioners.Grid

"""Even Length Grid Partitioner"""

import numpy as np
import math
import random as rnd
import functools, operator
from pyFTS.common import FuzzySet, Membership
from pyFTS.partitioners import partitioner


class GridPartitioner(partitioner.Partitioner):
    """Even Length Grid Partitioner"""

    def __init__(self, **kwargs):
        """
        Even Length Grid Partitioner
        """
        super(GridPartitioner, self).__init__(name="Grid", **kwargs)

    def build(self, data):
        sets = {}

        kwargs = {'type': self.type, 'variable': self.variable}

        dlen = self.max - self.min
        partlen = dlen / self.partitions

        count = 0
        for c in np.arange(self.min, self.max, partlen):
            _name = self.get_name(count)
            if self.membership_function == Membership.trimf:
                sets[_name] = FuzzySet.FuzzySet(_name, Membership.trimf, [c - partlen, c, c + partlen],c,**kwargs)
            elif self.membership_function == Membership.gaussmf:
                sets[_name] = FuzzySet.FuzzySet(_name, Membership.gaussmf, [c, partlen / 3], c,**kwargs)
            elif self.membership_function == Membership.trapmf:
                q = partlen / 2
                sets[_name] = FuzzySet.FuzzySet(_name, Membership.trapmf, [c - partlen, c - q, c + q, c + partlen], c,**kwargs)
            count += 1

        self.min = self.min - partlen

        return sets