I am trying different classifiers with different parameters and stuff on a dataset provided to us as part of a course project. We have to try and get the best performance on the dataset. The dataset is actually a reduced version of the online news popularity
I have tried the SVM, Random Forest, SVM with cross-validation with k = 5 and they all seem to give approximately 100% training accuracy, while the testing accuracy is between 60-70. I think the testing accuracy is fine, but the training accuracy bothers me. I would say maybe it was a case of overfitting data but none of my classmates seem to be getting similar results so maybe the problem is with my code.
Here is the code for my cross-validation and random forest classifier. I would be very grateful if you help me find out why I am getting such a high Training accuracy
def crossValidation(X_train, X_test, y_train, y_test, numSplits):
skf = StratifiedKFold(n_splits=5, shuffle=True)
Cs = np.logspace(-3, 3, 10)
gammas = np.logspace(-3, 3, 10)
ACC = np.zeros((10, 10))
DEV = np.zeros((10, 10))
for i, gamma in enumerate(gammas):
for j, C in enumerate(Cs):
acc = []
for train_index, dev_index in skf.split(X_train, y_train):
X_cv_train, X_cv_dev = X_train[train_index], X_train[dev_index]
y_cv_train, y_cv_dev = y_train[train_index], y_train[dev_index]
clf = SVC(C=C, kernel='rbf', gamma=gamma, )
clf.fit(X_cv_train, y_cv_train)
acc.append(accuracy_score(y_cv_dev, clf.predict(X_cv_dev)))
ACC[i, j] = np.mean(acc)
DEV[i, j] = np.std(acc)
i, j = np.argwhere(ACC == np.max(ACC))[0]
clf1 = SVC(C=Cs[j], kernel='rbf', gamma=gammas[i], decision_function_shape='ovr')
clf1.fit(X_train, y_train)
y_predict_train = clf1.predict(X_train)
y_pred_test = clf1.predict(X_test)
print("Train Accuracy :: ", accuracy_score(y_train, y_predict_train))
print("Test Accuracy :: ", accuracy_score(y_test, y_pred_test))
def randomForestClassifier(X_train, X_test, y_train, y_test):
"""
clf = RandomForestClassifier()
clf.fit(X_train, y_train)
y_predict_train = clf.predict(X_train)
y_pred_test = clf.predict(X_test)
print("Train Accuracy :: ", accuracy_score(y_train, y_predict_train))
print("Test Accuracy :: ", accuracy_score(y_test, y_pred_test))
There are two issues about the problem, training accuracy and testing accuracy are significantly different.
Since you apply cross-validation, it seems that you should think about another solution. I recommend that you apply some feature selection or feature reduction (like PCA) approaches to tackle the overfitting problem.
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