Using PCA
In this exercise, you'll apply PCA to the wine
dataset, to see if you can increase the model's accuracy.
Cet exercice fait partie du cours
Preprocessing for Machine Learning in Python
Instructions
- Instantiate a
PCA
object. - Define the features (
X
) and labels (y
) fromwine
, using the labels in the"Type"
column. - Apply PCA to
X_train
andX_test
, ensuring no data leakage, and store the transformed values aspca_X_train
andpca_X_test
. - Print out the
.explained_variance_ratio_
attribute ofpca
to check how much variance is explained by each component.
Exercice interactif pratique
Essayez cet exercice en complétant cet exemple de code.
# Instantiate a PCA object
pca = ____()
# Define the features and labels from the wine dataset
X = wine.drop(____, ____)
y = wine["Type"]
X_train, X_test, y_train, y_test = train_test_split(X, y, stratify=y, random_state=42)
# Apply PCA to the wine dataset X vector
pca_X_train = ___.____(____)
pca_X_test = ___.____(____)
# Look at the percentage of variance explained by the different components
print(____)