Enhance partition (#16)

#15 Create impurity function in Stree (consistent name, same criteria as other splitter parameter)
Create test for the new function
Update init test
Update test splitter parameters
Rename old impurity function to partition_impurity
close #15
* Complete implementation of splitter_type = impurity with tests
Remove max_distance & min_distance splitter types

* Fix mistake in computing multiclass node belief
Set default criterion for split to entropy instead of gini
Set default max_iter to 1e5 instead of 1e3
change up-down criterion to match SVC multiclass
Fix impurity method of splitting nodes
Update jupyter Notebooks
This commit is contained in:
Ricardo Montañana Gómez
2020-11-03 11:36:05 +01:00
committed by GitHub
parent f5706c3159
commit 1c869e154e
10 changed files with 879 additions and 289 deletions

View File

@@ -5,6 +5,7 @@ import warnings
import numpy as np
from sklearn.datasets import load_iris, load_wine
from sklearn.exceptions import ConvergenceWarning
from sklearn.svm import LinearSVC
from stree import Stree, Snode
from .utils import load_dataset
@@ -41,23 +42,22 @@ class Stree_test(unittest.TestCase):
_, count_u = np.unique(y_up, return_counts=True)
#
for i in unique_y:
number_down = count_d[i]
number_up = count_u[i]
try:
number_up = count_u[i]
number_down = count_d[i]
except IndexError:
number_up = 0
number_down = 0
self.assertEqual(count_y[i], number_down + number_up)
# Is the partition made the same as the prediction?
# as the node is not a leaf...
_, count_yp = np.unique(y_prediction, return_counts=True)
self.assertEqual(count_yp[0], y_up.shape[0])
self.assertEqual(count_yp[1], y_down.shape[0])
self.assertEqual(count_yp[1], y_up.shape[0])
self.assertEqual(count_yp[0], y_down.shape[0])
self._check_tree(node.get_down())
self._check_tree(node.get_up())
def test_build_tree(self):
"""Check if the tree is built the same way as predictions of models
"""
"""Check if the tree is built the same way as predictions of models"""
warnings.filterwarnings("ignore")
for kernel in self._kernels:
clf = Stree(kernel=kernel, random_state=self._random_state)
@@ -99,20 +99,22 @@ class Stree_test(unittest.TestCase):
self.assertListEqual(yp_line.tolist(), yp_once.tolist())
def test_iterator_and_str(self):
"""Check preorder iterator
"""
"""Check preorder iterator"""
expected = [
"root feaures=(0, 1, 2) impurity=0.5000",
"root - Down feaures=(0, 1, 2) impurity=0.0671",
"root - Down - Down, <cgaf> - Leaf class=1 belief= 0.975989 "
"impurity=0.0469 counts=(array([0, 1]), array([ 17, 691]))",
"root - Down - Up feaures=(0, 1, 2) impurity=0.3967",
"root - Down - Up - Down, <cgaf> - Leaf class=1 belief= 0.750000 "
"impurity=0.3750 counts=(array([0, 1]), array([1, 3]))",
"root - Down - Up - Up, <pure> - Leaf class=0 belief= 1.000000 "
"impurity=0.0000 counts=(array([0]), array([7]))",
"root - Up, <cgaf> - Leaf class=0 belief= 0.928297 impurity=0.1331"
" counts=(array([0, 1]), array([725, 56]))",
"root feaures=(0, 1, 2) impurity=1.0000 counts=(array([0, 1]), arr"
"ay([750, 750]))",
"root - Down, <cgaf> - Leaf class=0 belief= 0.928297 impurity=0.37"
"22 counts=(array([0, 1]), array([725, 56]))",
"root - Up feaures=(0, 1, 2) impurity=0.2178 counts=(array([0, 1])"
", array([ 25, 694]))",
"root - Up - Down feaures=(0, 1, 2) impurity=0.8454 counts=(array("
"[0, 1]), array([8, 3]))",
"root - Up - Down - Down, <pure> - Leaf class=0 belief= 1.000000 i"
"mpurity=0.0000 counts=(array([0]), array([7]))",
"root - Up - Down - Up, <cgaf> - Leaf class=1 belief= 0.750000 imp"
"urity=0.8113 counts=(array([0, 1]), array([1, 3]))",
"root - Up - Up, <cgaf> - Leaf class=1 belief= 0.975989 impurity=0"
".1634 counts=(array([0, 1]), array([ 17, 691]))",
]
computed = []
expected_string = ""
@@ -188,44 +190,43 @@ class Stree_test(unittest.TestCase):
def test_muticlass_dataset(self):
datasets = {
"Synt": load_dataset(random_state=self._random_state, n_classes=3),
"Iris": load_iris(return_X_y=True),
"Iris": load_wine(return_X_y=True),
}
outcomes = {
"Synt": {
"max_samples linear": 0.9533333333333334,
"max_samples rbf": 0.836,
"max_samples poly": 0.9473333333333334,
"min_distance linear": 0.9533333333333334,
"min_distance rbf": 0.836,
"min_distance poly": 0.9473333333333334,
"max_distance linear": 0.9533333333333334,
"max_distance rbf": 0.836,
"max_distance poly": 0.9473333333333334,
"max_samples linear": 0.9606666666666667,
"max_samples rbf": 0.7133333333333334,
"max_samples poly": 0.49066666666666664,
"impurity linear": 0.9606666666666667,
"impurity rbf": 0.7133333333333334,
"impurity poly": 0.49066666666666664,
},
"Iris": {
"max_samples linear": 0.98,
"max_samples rbf": 1.0,
"max_samples poly": 1.0,
"min_distance linear": 0.98,
"min_distance rbf": 1.0,
"min_distance poly": 1.0,
"max_distance linear": 0.98,
"max_distance rbf": 1.0,
"max_distance poly": 1.0,
"max_samples linear": 1.0,
"max_samples rbf": 0.6910112359550562,
"max_samples poly": 0.6966292134831461,
"impurity linear": 1,
"impurity rbf": 0.6910112359550562,
"impurity poly": 0.6966292134831461,
},
}
for name, dataset in datasets.items():
px, py = dataset
for criteria in ["max_samples", "min_distance", "max_distance"]:
for criteria in ["max_samples", "impurity"]:
for kernel in self._kernels:
clf = Stree(
C=1e4,
max_iter=1e4,
C=55,
max_iter=1e5,
kernel=kernel,
random_state=self._random_state,
)
clf.fit(px, py)
outcome = outcomes[name][f"{criteria} {kernel}"]
# print(
# f"{name} {criteria} {kernel} {outcome} {clf.score(px"
# ", py)}"
# )
self.assertAlmostEqual(outcome, clf.score(px, py))
def test_max_features(self):
@@ -297,7 +298,10 @@ class Stree_test(unittest.TestCase):
0.9433333333333334,
]
for kernel, accuracy_expected in zip(self._kernels, accuracies):
clf = Stree(random_state=self._random_state, kernel=kernel,)
clf = Stree(
random_state=self._random_state,
kernel=kernel,
)
clf.fit(X, y)
accuracy_score = clf.score(X, y)
yp = clf.predict(X)
@@ -309,75 +313,7 @@ class Stree_test(unittest.TestCase):
X, y = load_dataset(self._random_state)
clf = Stree(random_state=self._random_state, max_features=2)
clf.fit(X, y)
self.assertAlmostEqual(0.9426666666666667, clf.score(X, y))
def test_score_multi_class(self):
warnings.filterwarnings("ignore")
accuracies = [
0.8258427, # Wine linear min_distance
0.6741573, # Wine linear max_distance
0.8314607, # Wine linear max_samples
0.6629213, # Wine rbf min_distance
1.0000000, # Wine rbf max_distance
0.4044944, # Wine rbf max_samples
0.9157303, # Wine poly min_distance
1.0000000, # Wine poly max_distance
0.7640449, # Wine poly max_samples
0.9933333, # Iris linear min_distance
0.9666667, # Iris linear max_distance
0.9666667, # Iris linear max_samples
0.9800000, # Iris rbf min_distance
0.9800000, # Iris rbf max_distance
0.9800000, # Iris rbf max_samples
1.0000000, # Iris poly min_distance
1.0000000, # Iris poly max_distance
1.0000000, # Iris poly max_samples
0.8993333, # Synthetic linear min_distance
0.6533333, # Synthetic linear max_distance
0.9313333, # Synthetic linear max_samples
0.8320000, # Synthetic rbf min_distance
0.6660000, # Synthetic rbf max_distance
0.8320000, # Synthetic rbf max_samples
0.6066667, # Synthetic poly min_distance
0.6840000, # Synthetic poly max_distance
0.6340000, # Synthetic poly max_samples
]
datasets = [
("Wine", load_wine(return_X_y=True)),
("Iris", load_iris(return_X_y=True)),
(
"Synthetic",
load_dataset(self._random_state, n_classes=3, n_features=5),
),
]
for dataset_name, dataset in datasets:
X, y = dataset
for kernel in self._kernels:
for criteria in [
"min_distance",
"max_distance",
"max_samples",
]:
clf = Stree(
C=17,
random_state=self._random_state,
kernel=kernel,
split_criteria=criteria,
degree=5,
gamma="auto",
)
clf.fit(X, y)
accuracy_score = clf.score(X, y)
yp = clf.predict(X)
accuracy_computed = np.mean(yp == y)
# print(
# "{:.7f}, # {:7} {:5} {}".format(
# accuracy_score, dataset_name, kernel, criteria
# )
# )
accuracy_expected = accuracies.pop(0)
self.assertEqual(accuracy_score, accuracy_computed)
self.assertAlmostEqual(accuracy_expected, accuracy_score)
self.assertAlmostEqual(0.944, clf.score(X, y))
def test_bogus_splitter_parameter(self):
clf = Stree(splitter="duck")
@@ -407,10 +343,102 @@ class Stree_test(unittest.TestCase):
original = weights_no_zero.copy()
clf = Stree()
clf.fit(X, y)
node = clf.train(X, y, weights, 1, "test",)
node = clf.train(
X,
y,
weights,
1,
"test",
)
# if a class is lost with zero weights the patch adds epsilon
self.assertListEqual(weights.tolist(), weights_epsilon)
self.assertListEqual(node._sample_weight.tolist(), weights_epsilon)
# zero weights are ok when they don't erase a class
_ = clf.train(X, y, weights_no_zero, 1, "test")
self.assertListEqual(weights_no_zero.tolist(), original.tolist())
def test_multiclass_classifier_integrity(self):
"""Checks if the multiclass operation is done right"""
X, y = load_iris(return_X_y=True)
clf = Stree(random_state=0)
clf.fit(X, y)
score = clf.score(X, y)
# Check accuracy of the whole model
self.assertAlmostEquals(0.98, score, 5)
svm = LinearSVC(random_state=0)
svm.fit(X, y)
self.assertAlmostEquals(0.9666666666666667, svm.score(X, y), 5)
data = svm.decision_function(X)
expected = [
0.4444444444444444,
0.35777777777777775,
0.4569777777777778,
]
ty = data.copy()
ty[data <= 0] = 0
ty[data > 0] = 1
ty = ty.astype(int)
for i in range(3):
self.assertAlmostEquals(
expected[i],
clf.splitter_._gini(ty[:, i]),
)
# 1st Branch
# up has to have 50 samples of class 0
# down should have 100 [50, 50]
up = data[:, 2] > 0
resup = np.unique(y[up], return_counts=True)
resdn = np.unique(y[~up], return_counts=True)
self.assertListEqual([1, 2], resup[0].tolist())
self.assertListEqual([3, 50], resup[1].tolist())
self.assertListEqual([0, 1], resdn[0].tolist())
self.assertListEqual([50, 47], resdn[1].tolist())
# 2nd Branch
# up should have 53 samples of classes [1, 2] [3, 50]
# down shoud have 47 samples of class 1
node_up = clf.tree_.get_down().get_up()
node_dn = clf.tree_.get_down().get_down()
resup = np.unique(node_up._y, return_counts=True)
resdn = np.unique(node_dn._y, return_counts=True)
self.assertListEqual([1, 2], resup[0].tolist())
self.assertListEqual([3, 50], resup[1].tolist())
self.assertListEqual([1], resdn[0].tolist())
self.assertListEqual([47], resdn[1].tolist())
def test_score_multiclass_rbf(self):
X, y = load_dataset(
random_state=self._random_state,
n_classes=3,
n_features=5,
n_samples=500,
)
clf = Stree(kernel="rbf", random_state=self._random_state)
self.assertEqual(0.824, clf.fit(X, y).score(X, y))
X, y = load_wine(return_X_y=True)
self.assertEqual(0.6741573033707865, clf.fit(X, y).score(X, y))
def test_score_multiclass_poly(self):
X, y = load_dataset(
random_state=self._random_state,
n_classes=3,
n_features=5,
n_samples=500,
)
clf = Stree(
kernel="poly", random_state=self._random_state, C=10, degree=5
)
self.assertEqual(0.786, clf.fit(X, y).score(X, y))
X, y = load_wine(return_X_y=True)
self.assertEqual(0.702247191011236, clf.fit(X, y).score(X, y))
def test_score_multiclass_linear(self):
X, y = load_dataset(
random_state=self._random_state,
n_classes=3,
n_features=5,
n_samples=1500,
)
clf = Stree(kernel="linear", random_state=self._random_state)
self.assertEqual(0.9533333333333334, clf.fit(X, y).score(X, y))
X, y = load_wine(return_X_y=True)
self.assertEqual(0.9550561797752809, clf.fit(X, y).score(X, y))