Axis aligned artifacts
There are artifacts created by choosing axis aligned cuts in robust random cut forests, similar to what was noted with IsoForest..
Left: Original data distribution. Right: Learned co-displacement, darker is lower.
Notice the echoes around (10,-10) and (-10, 10)
If instead of either of these, you use the depth in the robust random cut forest, you get what’s shown above. The first two examples are recreated by the code below: