Anomaly Detection Guide
Def:
Anomaly Detection is the technique of identifying rare events or observations which can raise suspicions, deviate significantly from the majority of the data
Concepts:
Point & Collective
Local Anomaly:
A Local Anomaly is the observation group that is deviate from the NN(nearest Neighbourhood, it could be a point or collective), as figure above,
Global Anomaly:
The observation group that is deviate from the all observations,
Method:
KNN Anomaly Detection Isolation Forest