testing bandwidth selection as internal model selection with reduction

This commit is contained in:
Alejandro Moreo Fernandez 2024-09-24 17:10:04 +02:00
parent 84f5799219
commit 2aabfdc4c0
4 changed files with 110 additions and 33 deletions

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@ -4,13 +4,15 @@ from sklearn.base import BaseEstimator
from sklearn.neighbors import KernelDensity
import quapy as qp
from quapy.protocol import UPP
from quapy.method._kdey import KDEBase
from quapy.data import LabelledCollection
from quapy.method.aggregative import AggregativeSoftQuantifier, KDEyML
import quapy.functional as F
from sklearn.metrics.pairwise import rbf_kernel
from scipy import optimize
from tqdm import tqdm
epsilon = 1e-10
@ -63,10 +65,6 @@ class KDEyMLauto(KDEyML):
current_prevalence, current_bandwidth = self.optim_minimize_both(current_bandwidth, current_prevalence, tr_posteriors, tr_y, te_posteriors, classes)
elif self.optim == 'both_fine':
current_prevalence, current_bandwidth = self.optim_minimize_both_fine(current_bandwidth, current_prevalence, tr_posteriors, tr_y, te_posteriors, classes)
elif self.optim == 'both_fine':
current_prevalence, current_bandwidth = self.optim_minimize_both_fine(current_bandwidth, current_prevalence, tr_posteriors, tr_y, te_posteriors, classes)
# elif self.optim == 'max_likelihood':
# current_prevalence, current_bandwidth = self.optim_minimize_like(current_bandwidth, current_prevalence, tr_posteriors, tr_y, te_posteriors, classes)
# check converngece
prev_convergence = all(np.isclose(previous_prevalence, current_prevalence, atol=0.0001))
@ -256,3 +254,73 @@ def optim_minimize(loss: Callable, init_prev: np.ndarray, return_loss=False):
else:
return r.x
class KDEyMLauto2(KDEyML):
def __init__(self, classifier: BaseEstimator=None, val_split=5, bandwidth=0.1, random_state=None, reduction=100, max_reduced=500, target='likelihood'):
"""
reduction: number of examples per class for automatically setting the bandwidth
"""
self.classifier = qp._get_classifier(classifier)
self.val_split = val_split
if bandwidth == 'auto':
self.bandwidth = bandwidth
else:
self.bandwidth = KDEBase._check_bandwidth(bandwidth)
self.reduction = reduction
self.max_reduced = max_reduced
self.random_state = random_state
assert target == 'likelihood' or target in qp.error.QUANTIFICATION_ERROR_NAMES, 'unknown target for auto'
self.target = target
def aggregation_fit(self, classif_predictions: LabelledCollection, data: LabelledCollection):
if self.bandwidth == 'auto':
self.auto_bandwidth_likelihood(classif_predictions)
else:
self.bandwidth_ = self.bandwidth
self.mix_densities = self.get_mixture_components(*classif_predictions.Xy, data.classes_, self.bandwidth_)
return self
def auto_bandwidth_likelihood(self, classif_predictions: LabelledCollection):
n_classes = classif_predictions.n_classes
train, val = classif_predictions.split_stratified(train_prop=0.5, random_state=self.random_state)
if self.reduction is not None:
# reduce samples to speed up computation
tr_length = min(self.reduction * n_classes, self.max_reduced)
if len(train) > tr_length:
train = train.sampling(tr_length)
best_band = None
best_loss_val = None
init_prev = np.full(fill_value=1 / n_classes, shape=(n_classes,))
for bandwidth in np.logspace(-4, np.log10(0.2), 20):
mix_densities = self.get_mixture_components(*train.Xy, train.classes_, bandwidth)
repeats = 25
loss_accum = 0
prot = UPP(val, sample_size=self.reduction, repeats=repeats, random_state=self.random_state)
for (sample, prev) in tqdm(prot(), total=repeats):
test_densities = [self.pdf(kde_i, sample) for kde_i in mix_densities]
def neg_loglikelihood_prev_(prev):
test_mixture_likelihood = sum(prev_i * dens_i for prev_i, dens_i in zip(prev, test_densities))
test_loglikelihood = np.log(test_mixture_likelihood + epsilon)
return -np.sum(test_loglikelihood)
if self.target == 'likelihood':
loss_fn = neg_loglikelihood_prev_
else:
loss_fn = lambda prev_hat: qp.error.from_name(self.target)(prev, prev_hat)
pred_prev, loss_val = optim_minimize(loss_fn, init_prev, return_loss=True)
loss_accum += loss_val
if best_loss_val is None or loss_accum < best_loss_val:
best_loss_val = loss_accum
best_band = bandwidth
print(f'found bandwidth={best_band:.4f} (loss_val={best_loss_val:.5f})')
self.bandwidth_ = best_band

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@ -7,7 +7,7 @@ import numpy as np
from sklearn.linear_model import LogisticRegression
import quapy as qp
from KDEy.kdey_devel import KDEyMLauto
from KDEy.kdey_devel import KDEyMLauto, KDEyMLauto2
from quapy.method.aggregative import PACC, EMQ, KDEyML
from quapy.model_selection import GridSearchQ
from quapy.protocol import UPP
@ -22,8 +22,8 @@ def newLR():
# typical hyperparameters explored for Logistic Regression
logreg_grid = {
'C': [1],
'class_weight': [None]
'C': np.logspace(-3,3,7),
'class_weight': [None, 'balanced']
}
@ -34,7 +34,12 @@ def wrap_hyper(classifier_hyper_grid: dict):
METHODS = [
('PACC', PACC(newLR()), wrap_hyper(logreg_grid)),
('EMQ', EMQ(newLR()), wrap_hyper(logreg_grid)),
('KDEy-ML', KDEyML(newLR()), {**wrap_hyper(logreg_grid), **{'bandwidth': np.logspace(-3, 0.5, 50)}}),
('KDEy-ML', KDEyML(newLR()), {**wrap_hyper(logreg_grid), **{'bandwidth': np.logspace(-4, np.log10(0.2), 20)}}),
('KDEy-ML-scott', KDEyML(newLR(), bandwidth='scott'), wrap_hyper(logreg_grid)),
('KDEy-ML-silver', KDEyML(newLR(), bandwidth='silverman'), wrap_hyper(logreg_grid)),
('KDEy-ML-autoLike', KDEyMLauto2(newLR(), bandwidth='auto', target='likelihood'), wrap_hyper(logreg_grid)),
('KDEy-ML-autoAE', KDEyMLauto2(newLR(), bandwidth='auto', target='mae'), wrap_hyper(logreg_grid)),
('KDEy-ML-autoRAE', KDEyMLauto2(newLR(), bandwidth='auto', target='mrae'), wrap_hyper(logreg_grid)),
]
@ -49,8 +54,8 @@ TRANSDUCTIVE_METHODS = [
# ('TKDEy-MLboth', KDEyMLauto(newLR(), optim='both'), None),
# ('TKDEy-MLbothfine', KDEyMLauto(newLR(), optim='both_fine'), None),
# ('TKDEy-ML2', KDEyMLauto(newLR()), None),
('TKDEy-MLike', KDEyMLauto(newLR(), optim='max_likelihood'), None),
('TKDEy-MLike2', KDEyMLauto(newLR(), optim='max_likelihood2'), None),
# ('TKDEy-MLike', KDEyMLauto(newLR(), optim='max_likelihood'), None),
# ('TKDEy-MLike2', KDEyMLauto(newLR(), optim='max_likelihood2'), None),
#('TKDEy-ML3', KDEyMLauto(newLR()), None),
#('TKDEy-ML4', KDEyMLauto(newLR()), None),
]
@ -111,23 +116,27 @@ if __name__ == '__main__':
transductive_names = [name for (name, *_) in TRANSDUCTIVE_METHODS]
if method_name not in transductive_names:
# model selection (train)
train, val = train.split_stratified(random_state=SEED)
protocol = UPP(val, repeats=n_bags_val)
modsel = GridSearchQ(
quantifier, param_grid, protocol, refit=True, n_jobs=-1, verbose=1, error='mae'
)
t_init = time()
try:
modsel.fit(train)
print(f'best params {modsel.best_params_}')
print(f'best score {modsel.best_score_}')
quantifier = modsel.best_model()
except:
print('something went wrong... trying to fit the default model')
if len(param_grid) == 0:
t_init = time()
quantifier.fit(train)
train_time = time() - t_init
train_time = time() - t_init
else:
# model selection (train)
train, val = train.split_stratified(random_state=SEED)
protocol = UPP(val, repeats=n_bags_val)
modsel = GridSearchQ(
quantifier, param_grid, protocol, refit=True, n_jobs=-1, verbose=1, error='mae'
)
t_init = time()
try:
modsel.fit(train)
print(f'best params {modsel.best_params_}')
print(f'best score {modsel.best_score_}')
quantifier = modsel.best_model()
except:
print('something went wrong... trying to fit the default model')
quantifier.fit(train)
train_time = time() - t_init
else:
# transductive
t_init = time()

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@ -26,8 +26,8 @@ qp.environ['SAMPLE_SIZE'] = SAMPLE_SIZE
epsilon = 1e-10
# n_bags_test = 2
DATASETS = [qp.datasets.UCI_MULTICLASS_DATASETS[21]]
# DATASETS = qp.datasets.UCI_MULTICLASS_DATASETS
# DATASETS = [qp.datasets.UCI_MULTICLASS_DATASETS[21]]
DATASETS = qp.datasets.UCI_MULTICLASS_DATASETS
for i, dataset in enumerate(DATASETS):
data = qp.datasets.fetch_UCIMulticlassDataset(dataset)
n_classes = data.n_classes
@ -99,8 +99,8 @@ for i, dataset in enumerate(DATASETS):
# Pintar las series ae_error, rae_error, y kld_error en el primer eje Y
ax1.plot(xaxis, ae_error, label='AE Error', marker='o', color='b')
ax1.plot(xaxis, rae_error, label='RAE Error', marker='s', color='g')
ax1.plot(xaxis, kld_error, label='KLD Error', marker='^', color='r')
# ax1.plot(xaxis, rae_error, label='RAE Error', marker='s', color='g')
# ax1.plot(xaxis, kld_error, label='KLD Error', marker='^', color='r')
ax1.plot(xaxis, mse_error, label='MSE Error', marker='^', color='c')
ax1.set_xscale('log')
@ -124,7 +124,7 @@ for i, dataset in enumerate(DATASETS):
plt.title('Error Metrics vs Bandwidth')
# plt.show()
os.makedirs('./plots/likelihood/', exist_ok=True)
plt.savefig(f'./plots/likelihood/fig{it}.png')
plt.savefig(f'./plots/likelihood/{dataset}-fig{it}.png')
plt.close()

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@ -70,7 +70,7 @@ class KDEBase:
if selX.size == 0:
selX = [F.uniform_prevalence(len(classes))]
class_cond_X.append(selX)
if isinstance(bandwidth, float):
if isinstance(bandwidth, float) or isinstance(bandwidth, str):
bandwidth = np.full(fill_value=bandwidth, shape=(len(classes),))
return [self.get_kde_function(X_cond_yi, band_i) for X_cond_yi, band_i in zip(class_cond_X, bandwidth)]