KNN on scaled data
The accuracy score on the unscaled wine
dataset was decent, but let's see what you can achieve by using standardization. Once again, the knn
model as well as the X
and y
data and labels set have already been created for you.
This exercise is part of the course
Preprocessing for Machine Learning in Python
Exercise instructions
- Create the
StandardScaler()
method, stored in a variable namedscaler
. - Scale the training and test features, being careful not to introduce data leakage.
- Fit the
knn
model to the scaled training data. - Evaluate the model's performance by computing the test set accuracy.
Hands-on interactive exercise
Have a go at this exercise by completing this sample code.
X_train, X_test, y_train, y_test = train_test_split(X, y, stratify=y, random_state=42)
# Instantiate a StandardScaler
scaler = ____
# Scale the training and test features
X_train_scaled = ____.____(____)
X_test_scaled = ____.____(____)
# Fit the k-nearest neighbors model to the training data
____.____(____, ____)
# Score the model on the test data
print(____.____(____, ____))