[ 
https://issues.apache.org/jira/browse/SPARK-14681?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16391762#comment-16391762
 ] 

Joseph K. Bradley commented on SPARK-14681:
-------------------------------------------

[~WeichenXu123] Thanks for the PR!  I'll comment on the design here in the JIRA.

>From your PR:
{code}
class TreeClassifierStatInfo
   def getLabelCount(label: Int): Double

class TreeRegressorStatInfo
   def getCount(): Double
   def getSum(): Double
   def getSquareSum(): Double

class Node
   ....
   +++ def statInfo: TreeStatInfo

trait TreeStatInfo
   def asTreeClassifierStatInfo: TreeClassifierStatInfo
   def asTreeRegressorStatInfo: TreeRegressorStatInfo
{code}

I have a few thoughts:
* I like the overall approach of using classes instead of just returning plain 
double arrays.
* This will require users to explicitly cast TreeStatInfo to the 
classifier/regressor type.  Would it be possible to avoid that without breaking 
APIs, e.g., by having a ClassificationNode and a RegressionNode inheriting from 
Node?
* Naming: What about using "Stats" or "Statistics" instead of "StatInfo?"  I 
just feel the "Info" part is uninformative.

> Provide label/impurity stats for spark.ml decision tree nodes
> -------------------------------------------------------------
>
>                 Key: SPARK-14681
>                 URL: https://issues.apache.org/jira/browse/SPARK-14681
>             Project: Spark
>          Issue Type: Improvement
>          Components: ML
>            Reporter: Joseph K. Bradley
>            Priority: Major
>
> Currently, spark.ml decision trees provide all node info except for the 
> aggregated stats about labels and impurities.  This task is to provide those 
> publicly.  We need to choose a good API for it, so we should discuss the 
> design on this issue before implementing it.



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)

---------------------------------------------------------------------
To unsubscribe, e-mail: issues-unsubscr...@spark.apache.org
For additional commands, e-mail: issues-h...@spark.apache.org

Reply via email to