from pyFTS.common import Membership, FuzzySet as FS
from pyFTS.common.Composite import FuzzySet as Composite
from pyFTS.partitioners import partitioner, Grid
from pyFTS.models.seasonal.common import DateTime, FuzzySet, strip_datepart
import numpy as np
import matplotlib.pylab as plt
[docs]class TimeGridPartitioner(partitioner.Partitioner):
"""Even Length DateTime Grid Partitioner"""
def __init__(self, **kwargs):
"""
Even Length Grid Partitioner
:param seasonality: Time granularity, from pyFTS.models.seasonal.common.DateTime
:param data: Training data of which the universe of discourse will be extracted. The universe of discourse is the open interval between the minimum and maximum values of the training data.
:param npart: The number of universe of discourse partitions, i.e., the number of fuzzy sets that will be created
:param func: Fuzzy membership function (pyFTS.common.Membership)
"""
super(TimeGridPartitioner, self).__init__(name="TimeGrid", preprocess=False, **kwargs)
self.season = kwargs.get('seasonality', DateTime.day_of_year)
data = kwargs.get('data', None)
if self.season == DateTime.year:
ndata = [strip_datepart(k, self.season) for k in data]
self.min = min(ndata)
self.max = max(ndata)
else:
tmp = (self.season.value / self.partitions) / 2
self.min = tmp
self.max = self.season.value + tmp
self.sets = self.build(None)
if self.ordered_sets is None and self.setnames is not None:
self.ordered_sets = self.setnames
else:
self.ordered_sets = FS.set_ordered(self.sets)
[docs] def build(self, data):
sets = {}
kwargs = {'variable': self.variable}
if self.season == DateTime.year:
dlen = (self.max - self.min)
partlen = dlen / self.partitions
else:
partlen = self.season.value / self.partitions
pl2 = partlen / 2
count = 0
for c in np.arange(self.min, self.max, partlen):
set_name = self.get_name(count)
if self.membership_function == Membership.trimf:
if c == self.min:
tmp = Composite(set_name, superset=True)
tmp.append_set(FuzzySet(self.season, set_name, Membership.trimf,
[self.season.value - pl2, self.season.value,
self.season.value + 0.0000001], self.season.value, alpha=.5,
**kwargs))
tmp.append_set(FuzzySet(self.season, set_name, Membership.trimf,
[c - partlen, c, c + partlen], c,
**kwargs))
tmp.centroid = c
sets[set_name] = tmp
else:
sets[set_name] = FuzzySet(self.season, set_name, Membership.trimf,
[c - partlen, c, c + partlen], c,
**kwargs)
elif self.membership_function == Membership.gaussmf:
sets[set_name] = FuzzySet(self.season, set_name, Membership.gaussmf, [c, partlen / 3], c,
**kwargs)
elif self.membership_function == Membership.trapmf:
q = partlen / 4
if c == self.min:
tmp = Composite(set_name, superset=True)
tmp.append_set(FuzzySet(self.season, set_name, Membership.trimf,
[self.season.value - pl2, self.season.value,
self.season.value + 0.0000001], 0,
**kwargs))
tmp.append_set(FuzzySet(self.season, set_name, Membership.trapmf,
[c - partlen, c - q, c + q, c + partlen], c,
**kwargs))
tmp.centroid = c
sets[set_name] = tmp
else:
sets[set_name] = FuzzySet(self.season, set_name, Membership.trapmf,
[c - partlen, c - q, c + q, c + partlen], c,
**kwargs)
count += 1
self.min = 0
return sets
[docs] def plot(self, ax):
"""
Plot the
:param ax:
:return:
"""
ax.set_title(self.name)
ax.set_ylim([0, 1])
ax.set_xlim([0, self.season.value])
ticks = []
x = []
for key in self.sets.keys():
s = self.sets[key]
if s.type == 'composite':
for ss in s.sets:
self.plot_set(ax, ss)
else:
self.plot_set(ax, s)
ticks.append(str(round(s.centroid, 0)) + '\n' + s.name)
x.append(s.centroid)
ax.xaxis.set_ticklabels(ticks)
ax.xaxis.set_ticks(x)
