Using outlier probabilities
An alternative to isolating outliers with contamination is using outlier probabilities. The best thing about this method is that you can choose an arbitrary probability threshold, which means you can be as confident as you want in the predictions.
IForest and big_mart are already loaded.
Deze oefening maakt deel uit van de cursus
Anomaly Detection in Python
Oefeninstructies
- Calculate probabilities for both inliers and outliers.
- Extract the probabilities for outliers into
outlier_probs. - Filter the outliers into
outliersby using a 70% threshold onoutlier_probs.
Praktische interactieve oefening
Probeer deze oefening eens door deze voorbeeldcode in te vullen.
iforest = IForest(random_state=10).fit(big_mart)
# Calculate probabilities
probs = iforest.____
# Extract the probabilities for outliers
outlier_probs = ____[____]
# Filter for when the probability is higher than 70%
outliers = ____[____]
print(len(outliers))