def test_train_and_predict(self):
# Load data set.
X = DataFrame(RANDOM_CLASSIFICATION_TEST_CASE['X'],
columns=['x1', 'x2', 'x3', 'x4', 'x5', 'x6', 'x7', 'x8', 'x9', 'x10'])
y = DataFrame(RANDOM_CLASSIFICATION_TEST_CASE['y'])
random_state = RANDOM_CLASSIFICATION_TEST_CASE['random_state']
expected_y_pred_by_algorithm = RANDOM_CLASSIFICATION_TEST_CASE['y_predicted']
expected_str_by_algorithm = RANDOM_CLASSIFICATION_TEST_CASE['str']
expected_hyperparams_by_algorithm = RANDOM_CLASSIFICATION_TEST_CASE['hyperparams']
expected_params_by_algorithm = RANDOM_CLASSIFICATION_TEST_CASE['params']
expected_descriptions_by_algorithm = RANDOM_CLASSIFICATION_TEST_CASE['description']
# Generate train/test split.
X_train, X_test, y_train, y_test = train_test_split(X, y, random_state=random_state)
# Iterate through SUPPORTED_ALGORITHMS.
for algorithm in SupervisedClassifier.SUPPORTED_ALGORITHMS:
log.info('Testing %s classifier...' % algorithm)
# Train model.
hyperparams = {'algorithm': algorithm, 'random_state': random_state}
# Default to stochastic search for expensive algorithms.
if algorithm in [SupervisedClassifier.RANDOM_FOREST]:
hyperparams['hyperparam_strategy'] = SupervisedClassifier.STOCHASTIC_SEARCH
# Test ability to force hyperparam values.
hyperparams['max_depth'] = 2
hyperparams['n_estimators'] = 5
hyperparams['min_samples_leaf'] = 1
hyperparams['min_samples_split'] = 0.2
else:
hyperparams['hyperparam_strategy'] = SupervisedClassifier.EXHAUSTIVE_SEARCH
classifier = SupervisedClassifier([0, 1], hyperparams)
classifier.train(X_train, y_train)
# Test str().
expected_str = expected_str_by_algorithm[algorithm]
actual_str = str(classifier)
self.assertEqual(expected_str, actual_str)
# Test hyperparameters.
expected_hyperparams = expected_hyperparams_by_algorithm[algorithm]
actual_hyperparams = classifier.hyperparams()
self._assert_equal_hyperparams(expected_hyperparams, actual_hyperparams)
# Test model parameters.
expected_params = expected_params_by_algorithm[algorithm]
actual_params = classifier.params()
self.assertEqualDict(expected_params, actual_params)
# Test model description.
expected_description = expected_descriptions_by_algorithm[algorithm]
actual_description = classifier.description()
self.assertEqual(expected_description, actual_description)
# Test prediction values.
expected_y_pred = expected_y_pred_by_algorithm[algorithm]
log.debug('expected_y_pred: %s' % expected_y_pred)
actual_y_pred = classifier.predict(X_test)
log.debug('actual_y_pred: %s' % actual_y_pred)
self.assertEqualList(expected_y_pred, actual_y_pred)
class BifurcatedSupervisedClassifier:
BIFURCATION = 'bifurcation'
EQUAL = '=='
LTE = '<='
GTE = '>='
SUPPORTED_BIFURCATION_STRATEGIES = [EQUAL, GTE, LTE]
def __init__(self, classes, hyperparams):
if hyperparams[
'bifurcation_strategy'] not in BifurcatedSupervisedClassifier.SUPPORTED_BIFURCATION_STRATEGIES:
raise ValueError('Bifurcation strategy %s not supported.' %
hyperparams['bifurcation_strategy'])
self._classes = classes
self._hyperparams = hyperparams
# Note that if we don't pass a copies of hyperparams, then we won't
# be able to change hyperparams independently in the two classifiers.
self._sc_true = SupervisedClassifier(classes, hyperparams.copy())
self._sc_false = SupervisedClassifier(classes, hyperparams.copy())
def __repr__(self):
bs = self._build_bifurcation_str()
classes_str = str(self._classes)
hyperparams_str = "hyperparams={'algorithm': %s, 'bifurcator': %s, 'bifurcation_strategy': %s, 'bifurcation_threshold': %s, 'random_state': %s}" % (
self._hyperparams['algorithm'], self._hyperparams['bifurcator'],
self._hyperparams['bifurcation_strategy'],
self._hyperparams['bifurcation_value'],
self._hyperparams['random_state'])
s = "BifurcatedSupervisedClassifier(%s, %s)" % (classes_str,
hyperparams_str)
return s
__str__ = __repr__
def _build_bifurcation_str(self):
args = (self._hyperparams['bifurcator'],
self._hyperparams['bifurcation_strategy'],
self._hyperparams['bifurcation_value'])
return '%s %s %s' % args
def fetch_bifurcation_masks(self, X):
log.debug('bifurcator: %s' % self._hyperparams['bifurcator'])
log.debug('bifurcation_strategy: %s' %
BifurcatedSupervisedClassifier.EQUAL)
log.debug('bifurcation_value: %s' %
self._hyperparams['bifurcation_value'])
if self._hyperparams[
'bifurcation_strategy'] is BifurcatedSupervisedClassifier.EQUAL:
true_mask = X[self._hyperparams['bifurcator']].astype(
float) == self._hyperparams['bifurcation_value']
false_mask = X[self._hyperparams['bifurcator']].astype(
float) != self._hyperparams['bifurcation_value']
elif self._hyperparams[
'bifurcation_strategy'] is BifurcatedSupervisedClassifier.LTE:
true_mask = X[self._hyperparams['bifurcator']].astype(
float) <= self._hyperparams['bifurcation_value']
false_mask = X[self._hyperparams['bifurcator']].astype(
float) > self._hyperparams['bifurcation_value']
elif self._hyperparams[
'bifurcation_strategy'] is BifurcatedSupervisedClassifier.GTE:
true_mask = X[self._hyperparams['bifurcator']].astype(
float) >= self._hyperparams['bifurcation_value']
false_mask = X[self._hyperparams['bifurcator']].astype(
float) < self._hyperparams['bifurcation_value']
log.debug('X[%s].value_counts(): %s' %
(self._hyperparams['bifurcator'],
X[self._hyperparams['bifurcator']].value_counts()))
log.debug('true_mask.value_counts(): %s' % true_mask.value_counts())
log.debug('false_mask.value_counts(): %s' % false_mask.value_counts())
return true_mask, false_mask
def description(self):
args = (self._hyperparams['algorithm'].upper().replace('-', '_'),
self._build_bifurcation_str(), self._sc_true.description(),
self._sc_false.description())
return 'BIFURCATED_%s(%s, true=%s, false=%s)' % args
def hyperparams(self):
hyperparams = {
'model_true': self._sc_true.hyperparams(),
'model_false': self._sc_false.hyperparams()
}
return hyperparams
def params(self):
params = {
'bifurcator': self._hyperparams['bifurcator'],
'bifurcation_strategy': self._hyperparams['bifurcation_strategy'],
'bifurcation_value': self._hyperparams['bifurcation_value'],
'model_true': self._sc_true.description(),
'model_false': self._sc_false.description()
}
return params
def train(self, X_train, y_train):
true_mask, false_mask = self.fetch_bifurcation_masks(X_train)
# Train sc_true.
X_train_true = X_train[true_mask]
y_train_true = y_train[true_mask]
status_true = self._sc_true.train(X_train_true, y_train_true)
if status_true == SupervisedClassifier.INSUFFICIENT_SAMPLES:
return status_true
# Train sc_true.
X_train_false = X_train[false_mask]
y_train_false = y_train[false_mask]
status_false = self._sc_false.train(X_train_false, y_train_false)
if status_false == SupervisedClassifier.INSUFFICIENT_SAMPLES:
return status_false
return SupervisedClassifier.TRAINED
def _stitch_disjoint_row(self, row):
if pd.isnull(row['y_pred_true']):
val = row['y_pred_false']
else:
val = row['y_pred_true']
return val
def _stitch_prob_0(self, row):
if pd.isnull(row['y_pred_prob_true_0']):
val = row['y_pred_prob_false_0']
else:
val = row['y_pred_prob_true_0']
return val
def _stitch_prob_1(self, row):
if pd.isnull(row['y_pred_prob_true_1']):
val = row['y_pred_prob_false_1']
else:
val = row['y_pred_prob_true_1']
return val
def _predict_label_or_probability(self, X_test, probability=None):
true_mask, false_mask = self.fetch_bifurcation_masks(X_test)
# Predict X_test_true.
X_test_true = X_test[true_mask]
if probability:
y_pred_true = self._sc_true.predict_probability(X_test_true)
else:
y_pred_true = self._sc_true.predict(X_test_true)
log.debug('y_pred_true: %s' % y_pred_true)
# Predict X_test_false.
X_test_false = X_test[false_mask]
if probability:
y_pred_false = self._sc_false.predict_probability(X_test_false)
else:
y_pred_false = self._sc_false.predict(X_test_false)
log.debug('y_pred_false: %s' % y_pred_false)
# Stitch results.
if probability:
column_names = ['y_pred_true_0', 'y_pred_true_1']
else:
column_names = ['y_pred_true']
y_pred_true_df = DataFrame(y_pred_true, index=X_test_true.index, \
columns=column_names)
log.debug('y_pred_true_df: %s' % y_pred_true_df)
if probability:
column_names = ['y_pred_false_0', 'y_pred_false_1']
else:
column_names = ['y_pred_false']
y_pred_false_df = DataFrame(y_pred_false, index=X_test_false.index, \
columns=column_names)
log.debug('y_pred_false_df: %s' % y_pred_false_df)
true_mask_df = DataFrame(true_mask)
mask_plus_true = true_mask_df.merge(y_pred_true_df, how='left', \
left_index=True, right_index=True)
mask_plus_true_plus_false = mask_plus_true.merge(y_pred_false_df, \
how='left', left_index=True, right_index=True)
mask_plus_true_plus_false['y_pred'] = mask_plus_true_plus_false.apply(
self._stitch_disjoint_row, axis=1)
log.debug('mask_plus_false: %s' % mask_plus_true_plus_false)
y_pred = mask_plus_true_plus_false['y_pred'].values
return y_pred
def predict(self, X_test):
true_mask, false_mask = self.fetch_bifurcation_masks(X_test)
# Predict X_test_true.
X_test_true = X_test[true_mask]
y_pred_true = self._sc_true.predict(X_test_true)
log.debug('y_pred_true: %s' % y_pred_true)
# Predict X_test_false.
X_test_false = X_test[false_mask]
y_pred_false = self._sc_false.predict(X_test_false)
log.debug('y_pred_false: %s' % y_pred_false)
# Stitch results.
column_names = ['y_pred_true']
y_pred_true_df = DataFrame(y_pred_true, index=X_test_true.index, \
columns=column_names)
log.debug('y_pred_true_df: %s' % y_pred_true_df)
column_names = ['y_pred_false']
y_pred_false_df = DataFrame(y_pred_false, index=X_test_false.index, \
columns=column_names)
log.debug('y_pred_false_df: %s' % y_pred_false_df)
true_mask_df = DataFrame(true_mask)
mask_plus_true = true_mask_df.merge(y_pred_true_df, how='left', \
left_index=True, right_index=True)
mask_plus_true_plus_false = mask_plus_true.merge(y_pred_false_df, \
how='left', left_index=True, right_index=True)
mask_plus_true_plus_false['y_pred'] = mask_plus_true_plus_false.apply(
self._stitch_disjoint_row, axis=1)
log.debug('mask_plus_false: %s' % mask_plus_true_plus_false)
y_pred = mask_plus_true_plus_false['y_pred'].values
return y_pred
def predict_probability(self, X_test):
true_mask, false_mask = self.fetch_bifurcation_masks(X_test)
# Predict X_test_true.
X_test_true = X_test[true_mask]
y_pred_prob_true = self._sc_true.predict_probability(X_test_true)
log.debug('y_pred_prob_true: %s' % y_pred_prob_true)
# Predict X_test_false.
X_test_false = X_test[false_mask]
y_pred_prob_false = self._sc_false.predict_probability(X_test_false)
log.debug('y_pred_prob_false: %s' % y_pred_prob_false)
# Stitch results.
column_names = ['y_pred_prob_true_0', 'y_pred_prob_true_1']
y_pred_prob_true_df = DataFrame(y_pred_prob_true, index=X_test_true.index, \
columns=column_names)
log.debug('y_pred_prob_true_df: %s' % y_pred_prob_true_df)
column_names = ['y_pred_prob_false_0', 'y_pred_prob_false_1']
y_pred_prob_false_df = DataFrame(y_pred_prob_false, index=X_test_false.index, \
columns=column_names)
log.debug('y_pred_prob_false_df: %s' % y_pred_prob_false_df)
true_mask_df = DataFrame(true_mask)
mask_plus_true = true_mask_df.merge(y_pred_prob_true_df, how='left', \
left_index=True, right_index=True)
composite = mask_plus_true.merge(y_pred_prob_false_df, \
how='left', left_index=True, right_index=True)
composite['y_pred_prob_0'] = composite.apply(self._stitch_prob_0,
axis=1)
composite['y_pred_prob_1'] = composite.apply(self._stitch_prob_1,
axis=1)
log.debug('composite: %s' % composite)
y_pred_prob = composite[['y_pred_prob_0', 'y_pred_prob_1']].values
log.debug(y_pred_prob)
return y_pred_prob
