Canberra distance measures the difference between two numeric records by summing each feature’s absolute difference relative to the sum of the corresponding absolute values. This normalizes each coordinate’s contribution by the scale of the two values, producing a distance somewhat similar to Manhattan distance. section 9.7.1
Three-feature calculation
For [0.1, 0.6, 0.2] and [0.5, 0.4, 0.7], the distance is 0.4/0.6 + 0.2/1.0 + 0.5/0.9, or approximately 1.42. Each term compares a feature difference with the scale of the two values. section 9.7.1
Apply Canberra distance when:
- Using distance or density-based outlier detectors such as KNN, KDE, or local outlier factor. section 9.7.1
- Comparing it with Minkowski, Manhattan, Euclidean, or Chebyshev distances for a particular outlier-detection project. section 9.7.1 section 9.8
