RegressionLeafNode
Leaf node; terminus of the tree walk for a given row, and the only node type that owns a live accumulator.
Inheritors
Properties
arm
The leaf's weighted-variance accumulator.
Functions
findLeaf
Walk to the leaf this row resolves to.
Public per-node subtree aggregate over all observations routed through this node (leaves: the arm snapshot; splits: the exact Chan-merge of both children plus any RegressionSplitNode.carryover). Lets callers score internal nodes — e.g. a Thompson walk-down that picks a branch by its subtree's posterior — without the tree having to keep a live arm on every split node. Equivalent to a directly-accumulated internal arm: Chan's parallel merge is exact for weighted-variance aggregates.
Freeze a live VectorView tree node into an immutable, serializable snapshot. Internal split aggregates are derived from the snapshotted children so the wire format stays stable even though live splits hold no arm.