def test_regression_hoeffding_tree_categorical_features(test_path):
data_path = os.path.join(test_path, 'ht_categorical_features_testcase.npy')
stream = np.load(data_path)
# Remove class value
stream = stream[:, np.delete(np.arange(8), 7)]
# Removes the last column (used only in the multi-target regression case)
stream = stream[:, :-1]
X, y = stream[:, :-1], stream[:, -1]
nominal_attr_idx = np.arange(7).tolist()
learner = RegressionHoeffdingTree(nominal_attributes=nominal_attr_idx)
learner.partial_fit(X, y)
expected_description = "if Attribute 4 = 0.0:\n" \
" Leaf = Statistics {0: 606.0000, 1: 1212.0000, 2: 3626.0000}\n" \
"if Attribute 4 = 1.0:\n" \
" Leaf = Statistics {0: 551.0000, 1: 1128.0000, 2: 3400.0000}\n" \
"if Attribute 4 = 2.0:\n" \
" Leaf = Statistics {0: 566.0000, 1: 1139.0000, 2: 3423.0000}\n" \
"if Attribute 4 = 3.0:\n" \
" Leaf = Statistics {0: 577.0000, 1: 1138.0000, 2: 3374.0000}\n" \
"if Attribute 4 = 4.0:\n" \
" Leaf = Statistics {0: 620.0000, 1: 1233.0000, 2: 3725.0000}\n" \
"if Attribute 4 = -3.0:\n" \
" Leaf = Statistics {0: 80.0000, 1: 163.0000, 2: 483.0000}\n"
assert SequenceMatcher(
None, expected_description, learner.get_model_description()
).ratio() > 0.9
def test_hoeffding_tree_perceptron():
stream = RegressionGenerator(n_samples=500,
n_features=20,
n_informative=15,
random_state=1)
stream.prepare_for_use()
learner = RegressionHoeffdingTree(leaf_prediction='perceptron',
random_state=1)
cnt = 0
max_samples = 500
y_pred = array('d')
y_true = array('d')
wait_samples = 10
while cnt < max_samples:
X, y = stream.next_sample()
# Test every n samples
if (cnt % wait_samples == 0) and (cnt != 0):
y_pred.append(learner.predict(X)[0])
y_true.append(y[0])
learner.partial_fit(X, y)
cnt += 1
expected_predictions = array('d', [
1198.4326121743168, 456.36607750881586, 927.9912160545144,
1160.4797981899128, 506.50541829176535, -687.8187227095925,
-677.8120094065415, 231.14888704761225, -284.46324039942937,
-255.69195985557175, 47.58787439365423, -135.22494016284043,
-10.351457437330152, 164.95903200643997, 360.72854984472383,
193.30633911830088, -64.23638301570358, 587.9771578214296,
649.8395655757931, 481.01214222804026, 305.4402728117724,
266.2096493865043, -445.11447171009775, -567.5748694154349,
-68.70070048021438, -446.79910655850153, -115.892348067663,
-98.26862866231015, 71.04707905920286, -10.239274802165584,
18.748731569441812, 4.971217265129857, 172.2223575990573,
-655.2864976783711, -129.69921313686626, -114.01187375876822,
-405.66166686550963, -215.1264381928009, -345.91020370426247,
-80.49330468453074, 108.78958382083302, 134.95267043280126,
-398.5273538477553, -157.1784910649728, 219.72541225645654,
-100.91598162899217, 80.9768574308987, -296.8856956382453,
251.9332271253148
])
assert np.allclose(y_pred, expected_predictions)
error = mean_absolute_error(y_true, y_pred)
expected_error = 362.98595964244623
assert np.isclose(error, expected_error)
expected_info = 'RegressionHoeffdingTree: max_byte_size: 33554432 - memory_estimate_period: 1000000 ' \
'- grace_period: 200 - split_criterion: variance reduction - split_confidence: 1e-07 ' \
'- tie_threshold: 0.05 - binary_split: False - stop_mem_management: False ' \
'- remove_poor_atts: False - no_pre_prune: False - leaf_prediction: perceptron - nb_threshold: 0 ' \
'- nominal_attributes: [] - '
assert learner.get_info() == expected_info
assert isinstance(learner.get_model_description(), type(''))
assert type(learner.predict(X)) == np.ndarray
def test_hoeffding_tree():
stream = RegressionGenerator(n_samples=500,
n_features=20,
n_informative=15,
random_state=1)
stream.prepare_for_use()
learner = RegressionHoeffdingTree(leaf_prediction='mean')
cnt = 0
max_samples = 500
y_pred = array('d')
y_true = array('d')
wait_samples = 10
while cnt < max_samples:
X, y = stream.next_sample()
# Test every n samples
if (cnt % wait_samples == 0) and (cnt != 0):
y_pred.append(learner.predict(X)[0])
y_true.append(y[0])
learner.partial_fit(X, y)
cnt += 1
expected_predictions = array('d', [
102.38946041769101, 55.6584574987656, 5.746076599168373,
17.11797209372667, 2.566888222752787, 9.188247802192826,
17.87894804676911, 15.940629626883966, 8.981172175448485,
13.152624115190092, 11.106058099429399, 6.473195313058236,
4.723621479590173, 13.825568609556493, 8.698873073880696,
1.6452441811010252, 5.123496188584294, 6.34387187194982,
5.9977733790395105, 6.874251577667707, 4.605348088338317,
8.20112636572672, 9.032631648758098, 4.428189978974459,
4.249801041367518, 9.983272668044492, 12.859518508979734,
11.741395774380285, 11.230028410261868, 9.126921979081521,
9.132146661688296, 7.750655625124709, 6.445145118245414,
5.760928671876355, 4.041291302080659, 3.591837600560529,
0.7640424010500604, 0.1738639840537784, 2.2068337802212286,
-81.05302946841077, 96.17757415335177, -77.35894903819677,
95.85568683733698, 99.1981674250886, 99.89327888035015,
101.66673013734784, -79.1904234513751, -80.42952143783687,
100.63954789983896
])
assert np.allclose(y_pred, expected_predictions)
error = mean_absolute_error(y_true, y_pred)
expected_error = 143.11351404083086
assert np.isclose(error, expected_error)
expected_info = 'RegressionHoeffdingTree: max_byte_size: 33554432 - memory_estimate_period: 1000000 ' \
'- grace_period: 200 - split_criterion: variance reduction - split_confidence: 1e-07 ' \
'- tie_threshold: 0.05 - binary_split: False - stop_mem_management: False ' \
'- remove_poor_atts: False - no_pre_prune: False - leaf_prediction: mean - nb_threshold: 0 ' \
'- nominal_attributes: [] - '
assert learner.get_info() == expected_info
assert isinstance(learner.get_model_description(), type(''))
assert type(learner.predict(X)) == np.ndarray
def test_hoeffding_tree_coverage(test_path):
# Cover nominal attribute observer
test_file = os.path.join(test_path, 'regression_data.npz')
data = np.load(test_file)
X = data['X']
y = data['y']
learner = RegressionHoeffdingTree(leaf_prediction='mean', nominal_attributes=[i for i in range(3)])
learner.partial_fit(X, y)
def test_hoeffding_tree_coverage(test_path):
# Cover nominal attribute observer
test_file = os.path.join(test_path, 'regression_data.npz')
data = np.load(test_file)
X = data['X']
y = data['y']
# Typo in leaf prediction
learner = RegressionHoeffdingTree(
leaf_prediction='percptron', nominal_attributes=[i for i in range(3)]
)
print(learner.split_criterion)
# Invalid split_criterion
learner.split_criterion = 'VR'
learner.partial_fit(X, y)
assert learner._estimator_type == 'regressor'
def test_regression_hoeffding_tree_model_description():
stream = RegressionGenerator(
n_samples=500, n_features=20, n_informative=15, random_state=1
)
stream.prepare_for_use()
learner = RegressionHoeffdingTree(leaf_prediction='mean')
max_samples = 500
X, y = stream.next_sample(max_samples)
learner.partial_fit(X, y)
expected_description = "if Attribute 6 <= 0.1394515530995348:\n" \
" Leaf = Statistics {0: 276.0000, 1: -21537.4157, 2: 11399392.2187}\n" \
"if Attribute 6 > 0.1394515530995348:\n" \
" Leaf = Statistics {0: 224.0000, 1: 22964.8868, 2: 10433581.2534}\n"
assert SequenceMatcher(
None, expected_description, learner.get_model_description()
).ratio() > 0.9