Time Series Analysis with Python Cookbook

8

Outlier Detection Using Statistical Methods

In addition to missing data, as discussed in Chapter 7, Handling Missing Data, a common data issue you may face is the presence of outliers. Outliers can be point outliers, collective outliers, or contextual outliers. For example, a point outlier occurs when a data point deviates from the rest of the population—sometimes referred to as a global outlier. Collective outliers, which are groups of observations, differ from the population and don't follow the expected pattern. Lastly, contextual outliers occur when an observation is considered an outlier based on a particular condition or context, such as deviation from neighboring data points. Note that with contextual outliers, the same observation ...