Source code for pyFTS.models.nonstationary.partitioners

import numpy as np
from pyFTS.partitioners import partitioner
from pyFTS.models.nonstationary import common, perturbation
from pyFTS.common import FuzzySet as stationary_fs


[docs]class PolynomialNonStationaryPartitioner(partitioner.Partitioner): """ Non Stationary Universe of Discourse Partitioner """ def __init__(self, data, part, **kwargs): """""" super(PolynomialNonStationaryPartitioner, self).__init__(name=part.name, data=data, npart=part.partitions, func=part.membership_function, names=part.setnames, prefix=part.prefix, transformation=part.transformation, indexer=part.indexer, preprocess=False) self.sets = {} loc_params, wid_params = self.get_polynomial_perturbations(data, **kwargs) if self.ordered_sets is None and self.setnames is not None: self.ordered_sets = part.setnames else: self.ordered_sets = stationary_fs.set_ordered(part.sets) for ct, key in enumerate(self.ordered_sets): set = part.sets[key] loc_roots = np.roots(loc_params[ct])[0] wid_roots = np.roots(wid_params[ct])[0] tmp = common.FuzzySet(set.name, set.mf, set.parameters, location=perturbation.polynomial, location_params=loc_params[ct], location_roots=loc_roots, #**kwargs) width=perturbation.polynomial, width_params=wid_params[ct], width_roots=wid_roots, **kwargs) self.sets[set.name] = tmp
[docs] def poly_width(self, par1, par2, rng, deg): a = np.polyval(par1, rng) b = np.polyval(par2, rng) diff = [b[k] - a[k] for k in rng] tmp = np.polyfit(rng, diff, deg=deg) return tmp
[docs] def scale_up(self,x,pct): if x > 0: return x*(1+pct) else: return x*pct
[docs] def scale_down(self,x,pct): if x > 0: return x*pct else: return x*(1+pct)
[docs] def get_polynomial_perturbations(self, data, **kwargs): w = kwargs.get("window_size", int(len(data) / 5)) degree = kwargs.get("degree", 2) xmax = [data[0]] tmax = [0] xmin = [data[0]] tmin = [0] l = len(data) for i in np.arange(0, l, w): sample = data[i:i + w] tx = max(sample) xmax.append(tx) tmax.append(np.ravel(np.argwhere(data == tx)).tolist()[0]) tn = min(sample) xmin.append(tn) tmin.append(np.ravel(np.argwhere(data == tn)).tolist()[0]) cmax = np.polyfit(tmax, xmax, deg=degree) cmin = np.polyfit(tmin, xmin, deg=degree) cmed = [] for d in np.arange(0, degree + 1): cmed.append(np.linspace(cmin[d], cmax[d], self.partitions)[1:self.partitions - 1]) loc_params = [cmin.tolist()] for i in np.arange(0, self.partitions - 2): tmp = [cmed[k][i] for k in np.arange(0, degree + 1)] loc_params.append(tmp) loc_params.append(cmax.tolist()) rng = np.arange(0, l) clen = [] for i in np.arange(1, self.partitions-1): tmp = self.poly_width(loc_params[i - 1], loc_params[i + 1], rng, degree) clen.append(tmp) tmp = self.poly_width(loc_params[0], loc_params[1], rng, degree) clen.insert(0, tmp) tmp = self.poly_width(loc_params[self.partitions-2], loc_params[self.partitions-1], rng, degree) clen.append(tmp) tmp = (loc_params, clen) return tmp
[docs] def build(self, data): pass
[docs]class SimpleNonStationaryPartitioner(partitioner.Partitioner): """ Non Stationary Universe of Discourse Partitioner """ def __init__(self, data, part, **kwargs): """""" super(SimpleNonStationaryPartitioner, self).__init__(name=part.name, data=data, npart=part.partitions, func=part.membership_function, names=part.setnames, prefix=part.prefix, transformation=part.transformation, indexer=part.indexer)#, preprocess=False) for key in part.sets.keys(): set = part.sets[key] tmp = common.FuzzySet(set.name, set.mf, set.parameters, **kwargs) tmp.centroid = set.centroid self.sets[key] =tmp self.ordered_sets = stationary_fs.set_ordered(self.sets)
[docs] def build(self, data): return {}
[docs]def simplenonstationary_gridpartitioner_builder(data, npart, transformation): from pyFTS.partitioners import Grid from pyFTS.models.nonstationary import perturbation, partitioners tmp_fs = Grid.GridPartitioner(data=data, npart=npart, transformation=transformation) fs = partitioners.SimpleNonStationaryPartitioner(data, tmp_fs, location=perturbation.polynomial, location_params=[1, 0], location_roots=0, width=perturbation.polynomial, width_params=[1, 0], width_roots=0) return fs