PDP report
target y · 3 features · 3 plotted
1 · Overview — where to look
An additive surrogate read off the global curves reproduces 85.8% of the model's predicted variance; adding the regional plots kept by the decision sequence, 99.8%.
Each point is a feature: importance (x) against heterogeneity (y). Bottom-left is ignorable; bottom-right is important and fully described by its mean effect; the top-right corner — important and heterogeneous — is where the mean hides something. An arrow marks each split the decision sequence accepted: from the feature's global point to its weighted-mean point across the subregions.
| # | feature | importance | heterogeneity | #regions | regional analysis |
|---|---|---|---|---|---|
| 1 | x3 | 0.6603 | 0.0000 | 1 | below the search threshold → |
| 2 | x2 | 0.3253 | 0.2960 | 7 | split found — rejected by the decision sequence → |
| 3 | x1 | 0.2959 | 0.0000 | 3 | split into 2 regions → |
The plotted features carry 100% of the total importance mass (target 80%, ceiling top_k = 5).
The decision sequence. Starting from the global curves, each round applies the split with the largest explained-variance gain, measured on top of the splits above it, and stops when no remaining split adds at least 1.0%. A real split (its heterogeneity does drop) can still add nothing — or even hurt, by double-counting — when its variance is already explained by an earlier split.
| step | regions | heterogeneity | explained variance |
|---|---|---|---|
| global effects (GAM) | · | · | 85.8% |
| + split x1 (on x2) | 2 | 0.299 → 0.000 | +14.0% → 99.8% |
| rejected · x2 (on x1) | 4 | 0.296 → 0.134 | -10.8% — redundant (variance already explained) |
Bar view — importance and heterogeneity
2 · Regional analysis — the final CALM
The selected snapshot: global effects everywhere except the accepted splits. Features in descending importance — a split feature enters as one group at the instance-weighted mean of its subregions. The split features' global counterparts are in the baseline section at the end.
2.1 · x3
Global effect
Regional effects
Heterogeneity below the threshold — the mean effect tells the whole story; find_regions was skipped.
2.2 · x2
Global effect
Regional effects
A split on x1 into 4 regions was found (heterogeneity 0.296 → 0.134), but the decision sequence skips it: it adds no explained variance beyond the splits kept there — the same variance is already read elsewhere. The regional plots are omitted; reproduce them with find_regions.
2.3 · x1
Split on x2 into 2 regions — worth +14.0% of explained variance on top of the splits above it; importance and heterogeneity here are the instance-weighted means over the subregions. The global counterpart is in the baseline.
Partition tree
Feature 0 - Full partition tree:
🌳 Full Tree Structure:
───────────────────────
x1 🔹 [id: 0 | heter: 0.30 | inst: 10000 | w: 1.00]
x2 < -0.00 🔹 [id: 1 | heter: 0.00 | inst: 4922 | w: 0.49]
x2 ≥ -0.00 🔹 [id: 2 | heter: 0.00 | inst: 5078 | w: 0.51]
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Feature 0 - Statistics per tree level:
🌳 Tree Summary:
─────────────────
Level 0🔹heter: 0.30
Level 1🔹heter: 0.00 | 🔻0.30 (100.00%)
3 · Global baseline — without regions
What you would believe about the split features without the regional analysis: their global mean effects, with the heterogeneity the accepted splits just explained still hiding inside the band. Compare with their subregions in the regional analysis above.
x1
