Github user MLnick commented on a diff in the pull request:
https://github.com/apache/spark/pull/12056#discussion_r57908437
--- Diff: python/pyspark/ml/classification.py ---
@@ -500,16 +500,12 @@ def featureImportances(self):
"""
Estimate of the importance of each feature.
- This generalizes the idea of "Gini" importance to other losses,
- following the explanation of Gini importance from "Random Forests"
documentation
- by Leo Breiman and Adele Cutler, and following the implementation
from scikit-learn.
+ Each feature's importance is the average of its importance across
all trees in the ensemble
--- End diff --
Fair enough - though the Scala doc should be updated likewise?
On Wed, 30 Mar 2016 at 17:21, Seth Hendrickson <[email protected]>
wrote:
> In python/pyspark/ml/classification.py
> <https://github.com/apache/spark/pull/12056#discussion_r57906908>:
>
> > @@ -500,16 +500,12 @@ def featureImportances(self):
> > """
> > Estimate of the importance of each feature.
> >
> > - This generalizes the idea of "Gini" importance to other losses,
> > - following the explanation of Gini importance from "Random
Forests" documentation
> > - by Leo Breiman and Adele Cutler, and following the
implementation from scikit-learn.
> > + Each feature's importance is the average of its importance
across all trees in the ensemble
>
> There was some discussion on this here
> <https://github.com/apache/spark/pull/11961>. Basically, since the random
> forest and GBT importance is just an average of the importances for single
> trees, we can just state that here and link to the doc for single trees,
> which explains how those are computed. Otherwise, we copy/paste the same
> explanation 6 times.
>
> â
> You are receiving this because you are subscribed to this thread.
> Reply to this email directly or view it on GitHub
>
<https://github.com/apache/spark/pull/12056/files/892d30123a192cd3796892c0f64a5cf2993e1f09#r57906908>
>
---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at [email protected] or file a JIRA ticket
with INFRA.
---
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
