Practicing standardization
It is dangerous to use KNN
on unknown distributions blindly. Its performance suffers greatly when the feature distributions don't have the same scales. Unscaled features will skew distance calculations and thus return unrealistic anomaly scores.
A common technique to counter this is using standardization, which involves removing the mean from a feature and dividing it by the standard deviation. This has the effect of making the feature have a mean of 0 and a variance of 1.
Practice standardization on the females
dataset, which has already been loaded for you.
Este exercício faz parte do curso
Anomaly Detection in Python
Instruções do exercício
- Create an instance of
StandardScaler()
and store it asss
. - Extract feature and target arrays into
X
andy
. The target is theweightkg
column. - Fit
StandardScaler()
to X and transform it simultaneously. - Repeat the above process but preserve the column names of the
X
DataFrame.
Exercício interativo prático
Experimente este exercício completando este código de exemplo.
from sklearn.preprocessing import StandardScaler
# Initialize a StandardScaler
ss = ____
# Extract feature and target arrays
X = ____
y = ____
# Fit/transform X
X_transformed = ____
# Fit/transform X but preserve the column names
X.____ = ____