def ada_boost(x_train, y_train, x_test, y_test, compute_threshold=False):
'''
Train an AdaBoost ensemble of Decision Trees on x_train and predict on x_test.
x_train, x_test: DataFrames of shape num_samples x num_features.
'''
from sklearn.ensemble import AdaBoostClassifier
from sklearn.tree import DecisionTreeClassifier
from sklearn.linear_model import LogisticRegression
# estimator = DecisionTreeClassifier(class_weight='balanced', criterion='entropy', max_depth=7, min_samples_leaf=5)
estimator = LogisticRegression(penalty='l2', C=1.0, solver='liblinear', n_jobs=1, max_iter=100)
model = AdaBoostClassifier(base_estimator=estimator, n_estimators=60, learning_rate=1.0)
metricsCV = cross_val_analysis(classifier=model, x=x_train, y=y_train, plot=False)
model.fit(x_train, y_train)
if compute_threshold is True:
probTest = model.predict_proba(x_test)
# probTrain = model.predict_proba(x_train)
bestThresh = get_best_thresh(y_train, probTrain)
predTest = np.where(probTest[:, 1] >= bestThresh, defs.posCode, defs.negCode)
plot_roc_curve(y_test, probTest, modelName="AdaBoost")
else:
predTest = model.predict(x_test)
return predTest, metricsCV, model
def gaussian_naive_bayes(x_train, y_train, x_test, y_test, compute_threshold=True):
'''
Train Naive Bayes classifier on x_train and predict on x_test
x_train, x_test: DataFrames of shape (data x features)
'''
from sklearn.naive_bayes import GaussianNB
model = GaussianNB(priors=None)
metricsCV = cross_val_analysis(classifier=model, x=x_train, y=y_train, plot=False)
model.fit(x_train, y_train)
if compute_threshold is True:
probTest = model.predict_proba(x_test)
probTrain = model.predict_proba(x_train)
bestThresh = get_best_thresh(y_train, probTrain)
predTest = np.where(probTest[:, 1] >= bestThresh, defs.posCode, defs.negCode)
plot_roc_curve(y_test, probTest, modelName="Naive Bayes")
else:
predTest = model.predict(x_test)
return predTest, metricsCV, model
def decision_tree(x_train, y_train, x_test, y_test, compute_threshold=True):
'''
Train a Decision Tree classifier on x_train and predict on x_test.
x_train, x_test: DataFrames of shape num_samples x num_features.
'''
from sklearn.tree import DecisionTreeClassifier
classWeights = {defs.posCode: 0.5, defs.negCode: 0.5}
model = DecisionTreeClassifier(class_weight='balanced',
criterion='entropy',
max_depth=15,
min_samples_leaf=5)
metricsCV = cross_val_analysis(classifier=model,
x=x_train,
y=y_train,
plot=False)
model.fit(x_train, y_train)
if compute_threshold is True:
probTest = model.predict_proba(x_test)
probTrain = model.predict_proba(x_train)
bestThresh = get_best_thresh(y_train, probTrain)
predTest = np.where(probTest[:, 1] >= bestThresh, defs.posCode,
defs.negCode)
plot_roc_curve(y_test, probTest, modelName="Decision Tree")
else:
predTest = model.predict(x_test)
return predTest, metricsCV, model
def log_reg(x_train, y_train, x_test, y_test, compute_threshold=True):
'''
Train Logistic Regression classifier on x_train and predict on x_test.
x_train, x_test: DataFrames of shape data x features.
thres: Class discrimination threshold
'''
from sklearn.linear_model import LogisticRegression
modelName = "Logistic Regression"
model = LogisticRegression(penalty='l2', C=1.0, solver='liblinear', n_jobs=1, max_iter=100)
#metricsCV = cross_val_analysis(classifier=model, x=x_train, y=y_train, plot=False)
metricsCV = 0
model.fit(x_train, y_train)#, weights) # TODO: Add class weights
if compute_threshold is True:
probTest = model.predict_proba(x_test)
probTrain = model.predict_proba(x_train)
bestThresh = get_best_thresh(y_train, probTrain)
predTest = np.where(probTest[:, 1] >= bestThresh, defs.posCode, defs.negCode)
# predTrain = np.where(probTrain[:, 1] >= bestThresh, defs.posCode, defs.negCode)
plot_roc_curve(y_test, probTest, modelName="Logistic Regression")
else:
predTest = model.predict(x_test)
# predTrain = model.predict(x_train)
return predTest, metricsCV, model
def nearest_neighbours(x_train,
y_train,
x_test,
y_test,
compute_threshold=True):
'''
Train K-Nearest Neighbours classifier on x_train and predict on x_test.
x_train, x_test: DataFrames of shape data x features.
'''
from sklearn.neighbors import KNeighborsClassifier
# TODO: Experiment with 'weights' parameter
# classWeights = {defs.posCode: 0.5, defs.negCode: 0.5}
model = KNeighborsClassifier(n_neighbors=3,
algorithm='ball_tree',
weights='uniform',
p=2,
metric='minkowski',
n_jobs=-1)
# print("\nParameters initialization:")
# print(percep.coef_)
metricsCV = cross_val_analysis(classifier=model,
x=x_train,
y=y_train,
plot=False)
model.fit(x_train, y_train) #, weights) # TODO: Add class weights
if compute_threshold is True:
probTest = model.predict_proba(x_test)
probTrain = model.predict_proba(x_train)
bestThresh = get_best_thresh(y_train, probTrain)
predTest = np.where(probTest[:, 1] >= bestThresh, defs.posCode,
defs.negCode)
plot_roc_curve(y_test, probTest, modelName="Nearest Neighbors")
else:
predTest = model.predict(x_test)
return predTest, metricsCV, model
def svm(x_train, y_train, x_test, y_test, compute_threshold=True):
'''
Train SVM classifier on x_train and predict on x_test.
x_train, x_test: DataFrames of shape data x features.
'''
from sklearn.svm import SVC
model = SVC(C=1.0,
cache_size=200,
class_weight=None,
coef0=0.0,
decision_function_shape='ovr',
degree=3,
gamma='auto',
kernel='rbf',
max_iter=-1,
probability=True,
random_state=None,
shrinking=True,
tol=0.001,
verbose=False)
metricsCV = cross_val_analysis(classifier=model,
x=x_train,
y=y_train,
plot=False)
model.fit(x_train, y_train)
if compute_threshold is True:
probTest = model.predict_proba(x_test)
probTrain = model.predict_proba(x_train)
bestThresh = get_best_thresh(y_train, probTrain)
predTest = np.where(probTest[:, 1] >= bestThresh, defs.posCode,
defs.negCode)
plot_roc_curve(y_test, probTest, modelName="SVM")
else:
predTest = model.predict(x_test)
return predTest, metricsCV, model
def linear_svm(x_train, y_train, x_test, y_test, compute_threshold=True):
'''
Train linear SVM classifier on x_train and predict on x_test.
x_train, x_test: DataFrames of shape data x features.
'''
from sklearn.svm import LinearSVC
model = LinearSVC(C=1.0,
class_weight=None,
dual=True,
fit_intercept=True,
intercept_scaling=1,
loss='squared_hinge',
max_iter=1000,
multi_class='ovr',
penalty='l2',
random_state=0,
tol=0.0001,
verbose=0)
metricsCV = cross_val_analysis(classifier=model,
x=x_train,
y=y_train,
plot=False)
model.fit(x_train, y_train)
if compute_threshold is True:
probTest = model.predict_proba(x_test)
probTrain = model.predict_proba(x_train)
bestThresh = get_best_thresh(y_train, probTrain)
predTest = np.where(probTest[:, 1] >= bestThresh, defs.posCode,
defs.negCode)
plot_roc_curve(y_test, probTest, modelName="SVM")
else:
predTest = model.predict(x_test)
return predTest, metricsCV, model
def linear_discriminant_analysis(x_train,
y_train,
x_test,
y_test,
n_components=2,
compute_threshold=True):
'''
Train Linear Discriminant Analysis (LDA) classifier on x_train and predict on x_test.
x_train, x_test: DataFrames of shape data x features.
n_components: Number of components (< n_classes - 1) for dimensionality reduction.
'''
from sklearn.discriminant_analysis import LinearDiscriminantAnalysis
# classWeights = {defs.posCode: 0.5, defs.negCode: 0.5}
model = LinearDiscriminantAnalysis(priors=None, n_components=n_components)
#X_r2 = model.fit(x_train, y_train).transform(X)
metricsCV = cross_val_analysis(classifier=model,
x=x_train,
y=y_train,
plot=False)
model.fit(x_train, y_train)
if compute_threshold is True:
probTest = model.predict_proba(x_test)
probTrain = model.predict_proba(x_train)
bestThresh = get_best_thresh(y_train, probTrain)
predTest = np.where(probTest[:, 1] >= bestThresh, defs.posCode,
defs.negCode)
plot_roc_curve(y_test,
probTest,
modelName="Linear Discriminant Analysis")
else:
predTest = model.predict(x_test)
return predTest, metricsCV, model
def mlp(x_train,
y_train,
x_test,
y_test,
hidden_neurons=10,
hidden_activation='tanh',
output_activation='tanh',
lossFunction='mean_squared_error',
optmizer='Adam',
metrics=['mae', 'mape', 'acc', 'categorical_accuracy'],
patience=30,
train_verbose=2,
n_epochs=500):
'''
Neural Networks classifier.
x_train, x_test: DataFrames of shape data x features.
'''
from keras.models import Sequential
from keras.layers import Dense
import keras.callbacks as callbacks
model = Sequential()
model.add(
Dense(hidden_neurons,
input_dim=x_train.shape[1],
activation=hidden_activation))
model.add(Dense(1, activation=output_activation))
model.compile(loss=lossFunction, optimizer=optmizer, metrics=metrics)
earlyStopping = callbacks.EarlyStopping(monitor='val_loss',
patience=patience,
verbose=train_verbose,
mode='auto')
history = model.fit(x_train,
y_train,
epochs=n_epochs,
callbacks=[earlyStopping],
verbose=train_verbose,
validation_data=(x_test, y_test))
metricsCV = cross_val_analysis(classifier=model,
x=x_train,
y=y_train,
plot=False)
model.fit(x_train, y_train)
if compute_threshold is True:
probTest = model.predict_proba(x_test)
probTrain = model.predict_proba(x_train)
bestThresh = get_best_thresh(y_train, probTrain)
predTest = np.where(probTest[:, 1] >= bestThresh, defs.posCode,
defs.negCode)
plot_roc_curve(y_test, probTest, modelName="SVM")
else:
predTest = model.predict(x_test)
return predTest, metricsCV, model
