QuaPy/BayesianKDEy/commons.py

146 lines
4.0 KiB
Python

import os
from functools import lru_cache
from pathlib import Path
from jax import numpy as jnp
from sklearn.base import BaseEstimator
import error
import functional as F
import quapy as qp
import numpy as np
from method.aggregative import KDEyML
from quapy.functional import l1_norm, ILRtransformation
from scipy.stats import entropy
def fetch_UCI_multiclass(data_name):
return qp.datasets.fetch_UCIMulticlassDataset(data_name, min_class_support=0.01)
def fetch_UCI_binary(data_name):
return qp.datasets.fetch_UCIBinaryDataset(data_name)
# global configurations
binary = {
'datasets': qp.datasets.UCI_BINARY_DATASETS.copy(),
'fetch_fn': fetch_UCI_binary,
'sample_size': 500
}
multiclass = {
'datasets': qp.datasets.UCI_MULTICLASS_DATASETS.copy(),
'fetch_fn': fetch_UCI_multiclass,
'sample_size': 1000
}
try:
multiclass['datasets'].remove('poker_hand') # random performance
multiclass['datasets'].remove('hcv') # random performance
multiclass['datasets'].remove('letter') # many classes
multiclass['datasets'].remove('isolet') # many classes
except ValueError:
pass
# utils
def experiment_path(dir:Path, dataset_name:str, method_name:str):
os.makedirs(dir, exist_ok=True)
return dir/f'{dataset_name}__{method_name}.pkl'
def normalized_entropy(p):
"""
Normalized Shannon entropy in [0, 1]
p: array-like, prevalence vector (sums to 1)
"""
p = np.asarray(p)
H = entropy(p) # Shannon entropy
H_max = np.log(len(p))
return np.clip(H / H_max, 0, 1)
def antagonistic_prevalence(p, strength=1):
ilr = ILRtransformation()
z = ilr(p)
z_ant = - strength * z
p_ant = ilr.inverse(z_ant)
return p_ant
class KDEyCLR(KDEyML):
def __init__(self, classifier: BaseEstimator=None, fit_classifier=True, val_split=5, bandwidth=1., random_state=None):
super().__init__(
classifier=classifier, fit_classifier=fit_classifier, val_split=val_split, bandwidth=bandwidth,
random_state=random_state, kernel='aitchison'
)
class KDEyILR(KDEyML):
def __init__(self, classifier: BaseEstimator=None, fit_classifier=True, val_split=5, bandwidth=1., random_state=None):
super().__init__(
classifier=classifier, fit_classifier=fit_classifier, val_split=val_split, bandwidth=bandwidth,
random_state=random_state, kernel='ilr'
)
class ILRtransformation(F.CompositionalTransformation):
def __init__(self, jax_mode=False):
self.jax_mode = jax_mode
def array(self, X):
if self.jax_mode:
return jnp.array(X)
else:
return np.asarray(X)
def __call__(self, X):
X = self.array(X)
X = qp.error.smooth(X, self.EPSILON)
k = X.shape[-1]
V = self.array(self.get_V(k))
logp = jnp.log(X) if self.jax_mode else np.log(X)
return logp @ V.T
def inverse(self, Z):
Z = self.array(Z)
k_minus_1 = Z.shape[-1]
k = k_minus_1 + 1
V = self.array(self.get_V(k))
logp = Z @ V
p = jnp.exp(logp) if self.jax_mode else np.exp(logp)
p = p / jnp.sum(p, axis=-1, keepdims=True) if self.jax_mode else p / np.sum(p, axis=-1, keepdims=True)
return p
@lru_cache(maxsize=None)
def get_V(self, k):
def helmert_matrix(k):
"""
Returns the (k x k) Helmert matrix.
"""
H = np.zeros((k, k))
for i in range(1, k):
H[i, :i] = 1
H[i, i] = -(i)
H[i] = H[i] / np.sqrt(i * (i + 1))
# row 0 stays zeros; will be discarded
return H
def ilr_basis(k):
"""
Constructs an orthonormal ILR basis using the Helmert submatrix.
Output shape: (k-1, k)
"""
H = helmert_matrix(k)
V = H[1:, :] # remove first row of zeros
return V
return ilr_basis(k)
def in_simplex(x):
return np.all(x >= 0) and np.isclose(x.sum(), 1)