pyFTS/pyFTS/hyperparam/Evolutionary.py
2019-06-17 09:25:47 -03:00

554 lines
16 KiB
Python

import numpy as np
import pandas as pd
import math
import time
from functools import reduce
from operator import itemgetter
import dispy
import random
from pyFTS.common import Util
from pyFTS.benchmarks import Measures
from pyFTS.partitioners import Grid, Entropy # , Huarng
from pyFTS.models import hofts
from pyFTS.common import Membership
from pyFTS.hyperparam import Util as hUtil
from pyFTS.distributed import dispy as dUtil
__measures = ['f1', 'f2', 'rmse', 'size']
def genotype(mf, npart, partitioner, order, alpha, lags, f1, f2):
'''
Create the individual genotype
:param mf: membership function
:param npart: number of partitions
:param partitioner: partitioner method
:param order: model order
:param alpha: alpha-cut
:param lags: array with lag indexes
:param f1: accuracy fitness value
:param f2: parsimony fitness value
:return: the genotype, a dictionary with all hyperparameters
'''
ind = dict(mf=mf, npart=npart, partitioner=partitioner, order=order,
alpha=alpha, lags=lags, f1=f1, f2=f2)
return ind
def random_genotype():
'''
Create random genotype
:return: the genotype, a dictionary with all hyperparameters
'''
order = random.randint(1, 3)
lags = [k for k in np.arange(1, order+1)]
return genotype(
random.randint(1, 4),
random.randint(10, 100),
random.randint(1, 2),
order,
random.uniform(0, .5),
lags,
None,
None
)
#
def initial_population(n):
'''
Create a random population of size n
:param n: the size of the population
:return: a list with n random individuals
'''
pop = []
for i in range(n):
pop.append(random_genotype())
return pop
def phenotype(individual, train, parameters={}):
'''
Instantiate the genotype, creating a fitted model with the genotype hyperparameters
:param individual: a genotype
:param train: the training dataset
:param parameters: dict with model specific arguments for fit method.
:return: a fitted FTS model
'''
try:
if individual['mf'] == 1:
mf = Membership.trimf
elif individual['mf'] == 2:
mf = Membership.trapmf
elif individual['mf'] == 3 and individual['partitioner'] != 2:
mf = Membership.gaussmf
else:
mf = Membership.trimf
#if individual['partitioner'] == 1:
partitioner = Grid.GridPartitioner(data=train, npart=individual['npart'], func=mf)
#elif individual['partitioner'] == 2:
# partitioner = Entropy.EntropyPartitioner(data=train, npart=individual['npart'], func=mf)
model = hofts.WeightedHighOrderFTS(partitioner=partitioner,
lags=individual['lags'],
alpha_cut=individual['alpha'],
order=individual['order'])
model.fit(train, **parameters)
return model
except Exception as ex:
print("PHENOTYPE EXCEPTION!", str(ex), str(individual))
return None
def evaluate(dataset, individual, **kwargs):
'''
Evaluate an individual using a sliding window cross validation over the dataset.
:param dataset: Evaluation dataset
:param individual: genotype to be tested
:param window_size: The length of scrolling window for train/test on dataset
:param train_rate: The train/test split ([0,1])
:param increment_rate: The increment of the scrolling window, relative to the window_size ([0,1])
:param parameters: dict with model specific arguments for fit method.
:return: a tuple (len_lags, rmse) with the parsimony fitness value and the accuracy fitness value
'''
from pyFTS.common import Util
from pyFTS.benchmarks import Measures
from pyFTS.hyperparam.Evolutionary import phenotype, __measures
import numpy as np
window_size = kwargs.get('window_size', 800)
train_rate = kwargs.get('train_rate', .8)
increment_rate = kwargs.get('increment_rate', .2)
parameters = kwargs.get('parameters',{})
if individual['f1'] is not None and individual['f2'] is not None:
return { key: individual[key] for key in __measures }
try:
errors = []
lengths = []
for count, train, test in Util.sliding_window(dataset, window_size, train=train_rate, inc=increment_rate):
model = phenotype(individual, train, parameters=parameters)
if model is None:
raise Exception("Phenotype returned None")
forecasts = model.predict(test)
rmse = Measures.rmse(test[model.max_lag:], forecasts) #.get_point_statistics(test, model)
lengths.append(len(model))
errors.append(rmse)
_lags = sum(model.lags) * 100
_rmse = np.nanmean(errors)
_len = np.nanmean(lengths)
f1 = np.nansum([.6 * _rmse, .4 * np.nanstd(errors)])
f2 = np.nansum([.4 * _len, .6 * _lags])
#print("EVALUATION {}".format(individual))
return {'f1': f1, 'f2': f2, 'rmse': _rmse, 'size': _len }
except Exception as ex:
#print("EVALUATION EXCEPTION!", str(ex), str(individual))
return {'f1': np.inf, 'f2': np.inf, 'rmse': np.inf, 'size': np.inf }
def tournament(population, objective):
'''
Simple tournament selection strategy.
:param population: the population
:param objective: the objective to be considered on tournament
:return:
'''
n = len(population) - 1
try:
r1 = random.randint(0, n) if n > 2 else 0
r2 = random.randint(0, n) if n > 2 else 1
ix = r1 if population[r1][objective] < population[r2][objective] else r2
return population[ix]
except Exception as ex:
print(r1, population[r1])
print(r2, population[r2])
raise ex
def double_tournament(population):
'''
Double tournament selection strategy.
:param population:
:return:
'''
ancestor1 = tournament(population, 'f1')
ancestor2 = tournament(population, 'f1')
selected = tournament([ancestor1, ancestor2], 'f2')
return selected
def lag_crossover2(best, worst):
'''
Cross over two lag genes
:param best: best genotype
:param worst: worst genotype
:return: a tuple (order, lags)
'''
order = int(round(.7 * best['order'] + .3 * worst['order']))
lags = []
min_order = min(best['order'], worst['order'])
max_order = best if best['order'] > min_order else worst
for k in np.arange(0, order):
if k < min_order:
lags.append(int(round(.7 * best['lags'][k] + .3 * worst['lags'][k])))
else:
lags.append(max_order['lags'][k])
for k in range(1, order):
while lags[k - 1] >= lags[k]:
lags[k] += random.randint(1, 10)
return order, lags
# Cruzamento
def crossover(parents):
'''
Crossover operation between two parents
:param parents: a list with two genotypes
:return: a genotype
'''
import random
n = len(parents) - 1
r1 = random.randint(0, n)
r2 = random.randint(0, n)
if parents[r1]['f1'] < parents[r2]['f1']:
best = parents[r1]
worst = parents[r2]
else:
best = parents[r2]
worst = parents[r1]
npart = int(round(.7 * best['npart'] + .3 * worst['npart']))
alpha = float(.7 * best['alpha'] + .3 * worst['alpha'])
rnd = random.uniform(0, 1)
mf = best['mf'] if rnd < .7 else worst['mf']
rnd = random.uniform(0, 1)
partitioner = best['partitioner'] if rnd < .7 else worst['partitioner']
order, lags = lag_crossover2(best, worst)
descendent = genotype(mf, npart, partitioner, order, alpha, lags, None, None)
return descendent
def mutation_lags(lags, order):
'''
Mutation operation for lags gene
:param lags:
:param order:
:return:
'''
try:
l = len(lags)
new = []
for lag in np.arange(order):
if lag < l:
new.append( min(50, max(1, int(lags[lag] + np.random.randint(-5, 5)))) )
else:
new.append( new[-1] + np.random.randint(1, 5) )
if order > 1:
for k in np.arange(1, order):
while new[k] <= new[k - 1]:
new[k] = int(new[k] + np.random.randint(1, 5))
return new
except Exception as ex:
print(lags, order, new, lag)
def mutation(individual, pmut):
'''
Mutation operator
:param population:
:return:
'''
import numpy.random
rnd = random.uniform(0, 1)
if rnd < pmut:
print('mutation')
individual['npart'] = min(50, max(3, int(individual['npart'] + np.random.normal(0, 4))))
individual['alpha'] = min(.5, max(0, individual['alpha'] + np.random.normal(0, .5)))
individual['mf'] = random.randint(1, 2)
individual['partitioner'] = random.randint(1, 2)
individual['order'] = min(5, max(1, int(individual['order'] + np.random.normal(0, 1))))
# Chama a função mutation_lags
individual['lags'] = mutation_lags( individual['lags'], individual['order'])
individual['f1'] = None
individual['f2'] = None
return individual
def elitism(population, new_population):
'''
Elitism operation, always select the best individual of the population and discard the worst
:param population:
:param new_population:
:return:
'''
population = sorted(population, key=itemgetter('f1'))
best = population[0]
new_population = sorted(new_population, key=itemgetter('f1'))
if new_population[0]["f1"] > best["f1"]:
new_population.insert(0,best)
elif new_population[0]["f1"] == best["f1"] and new_population[0]["f2"] > best["f2"]:
new_population.insert(0, best)
return new_population
def GeneticAlgorithm(dataset, **kwargs):
'''
Genetic algoritm for hyperparameter optimization
:param dataset:
:param ngen: Max number of generations
:param mgen: Max number of generations without improvement
:param npop: Population size
:param pcruz: Probability of crossover
:param pmut: Probability of mutation
:param window_size: The length of scrolling window for train/test on dataset
:param train_rate: The train/test split ([0,1])
:param increment_rate: The increment of the scrolling window, relative to the window_size ([0,1])
:param parameters: dict with model specific arguments for fit method.
:return: the best genotype
'''
statistics = []
ngen = kwargs.get('ngen',30)
mgen = kwargs.get('mgen', 7)
npop = kwargs.get('npop',20)
pcruz = kwargs.get('pcruz',.5)
pmut = kwargs.get('pmut',.3)
distributed = kwargs.get('distributed', False)
if distributed == 'dispy':
cluster = kwargs.pop('cluster', None)
collect_statistics = kwargs.get('collect_statistics', True)
no_improvement_count = 0
new_population = []
population = initial_population(npop)
last_best = population[0]
best = population[1]
print("Evaluating initial population {}".format(time.time()))
if not distributed:
for individual in population:
ret = evaluate(dataset, individual, **kwargs)
for key in __measures:
individual[key] = ret[key]
elif distributed=='dispy':
jobs = []
for ct, individual in enumerate(population):
job = cluster.submit(dataset, individual, **kwargs)
job.id = ct
jobs.append(job)
for job in jobs:
result = job()
if job.status == dispy.DispyJob.Finished and result is not None:
for key in __measures:
population[job.id][key] = result[key]
else:
print(job.exception)
print(job.stdout)
for i in range(ngen):
print("GENERATION {} {}".format(i, time.time()))
generation_statistics = {}
# Selection
for j in range(int(npop / 2)):
new_population.append(double_tournament(population))
new_population.append(double_tournament(population))
# Crossover
new = []
for j in range(int(npop * pcruz)):
new.append(crossover(new_population))
new_population.extend(new)
# Mutation
for ct, individual in enumerate(new_population):
new_population[ct] = mutation(individual, pmut)
# Evaluation
if collect_statistics:
stats = {}
for key in __measures:
stats[key] = []
if not distributed:
for individual in new_population:
ret = evaluate(dataset, individual, **kwargs)
for key in __measures:
individual[key] = ret[key]
if collect_statistics: stats[key].append(ret[key])
elif distributed == 'dispy':
jobs = []
for ct, individual in enumerate(new_population):
job = cluster.submit(dataset, individual, **kwargs)
job.id = ct
jobs.append(job)
for job in jobs:
print('job id {}'.format(job.id))
result = job()
if job.status == dispy.DispyJob.Finished and result is not None:
for key in __measures:
new_population[job.id][key] = result[key]
if collect_statistics: stats[key].append(result[key])
else:
print(job.exception)
print(job.stdout)
if collect_statistics:
mean_stats = {key: np.nanmedian(stats[key]) for key in __measures }
generation_statistics['population'] = mean_stats
# Elitism
population = elitism(population, new_population)
population = population[:npop]
new_population = []
last_best = best
best = population[0]
if collect_statistics:
generation_statistics['best'] = {key: best[key] for key in __measures }
statistics.append(generation_statistics)
if last_best['f1'] <= best['f1'] and last_best['f2'] <= best['f2']:
no_improvement_count += 1
print("WITHOUT IMPROVEMENT {}".format(no_improvement_count))
pmut += .05
else:
no_improvement_count = 0
pcruz = kwargs.get('pcruz', .5)
pmut = kwargs.get('pmut', .3)
print(best)
if no_improvement_count == mgen:
break
return best, statistics
def process_experiment(result, datasetname, conn):
log_result(conn, datasetname, result['individual'])
persist_statistics(result['statistics'])
return result['individual']
def persist_statistics(statistics):
import json
with open('statistics{}.txt'.format(time.time()), 'w') as file:
file.write(json.dumps(statistics))
def log_result(conn, datasetname, result):
metrics = ['rmse', 'size', 'time']
for metric in metrics:
record = (datasetname, 'Evolutive', 'WHOFTS', None, result['mf'],
result['order'], result['partitioner'], result['npart'],
result['alpha'], str(result['lags']), metric, result[metric])
print(record)
hUtil.insert_hyperparam(record, conn)
def execute(datasetname, dataset, **kwargs):
conn = hUtil.open_hyperparam_db('hyperparam.db')
experiments = kwargs.get('experiments', 30)
distributed = kwargs.get('distributed', False)
if distributed == 'dispy':
nodes = kwargs.get('nodes', ['127.0.0.1'])
cluster, http_server = dUtil.start_dispy_cluster(evaluate, nodes=nodes)
kwargs['cluster'] = cluster
ret = []
for i in np.arange(experiments):
print("Experiment {}".format(i))
start = time.time()
ret, statistics = GeneticAlgorithm(dataset, **kwargs)
end = time.time()
ret['time'] = end - start
experiment = {'individual': ret, 'statistics': statistics}
ret = process_experiment(experiment, datasetname, conn)
if distributed == 'dispy':
dUtil.stop_dispy_cluster(cluster, http_server)
return ret