4A) Histogram Based Outlier Score (HBOS)This is a statistical algorithmcreate a histogram for each feature in the datamultiply the inverse height of the feature bin that each bin resides in to get a feeling of the density a similar idea to the Naive Bayes algorithmoften used for fast semi-supervised anomaly detection the speed comes from ignoring the interdependencies of each feature with each other. This assumption is particularly safe when there’s a lot of one-off features that many other d...