Note, the SVDD appears to be good at detecting some categories of anomalies and poor at detecting others. For example, the SVDD correctly labels all five responses to CO 2 build-up (CO 2 ↑) as anomalous; they all fall outside of the decision boundary. On the other hand, the SVDD fails to detect all five anomalies where the C 2 H 4 supply is shut off (C 2 H 4 off); they all fall inside the decision boundary, with the majority of the normal responses. Green squares represent correctly predictions, red squares mis-classifications.