combust/mleap

Support multiple input columns for Bucketizer and StringIndexer as with spark.

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#549 opened on Aug 21, 2019

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 (0 comments) (0 reactions) (0 assignees)Scala (1,461 stars) (312 forks)batch import
enhancementhelp wanted

Description

Currently transformers in spark such as bucketizer and stringindexer have multiple-input support, maybe mleap should keep up with it.

Contributor guide

Tech stack
scalaspark
Domain
machine learning
Issue type
feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
4
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
3-5 days
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
mostly clear
Prerequisites
ScalaMLeap internalsSpark ML transformersBasic ML pipeline concepts
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
20
Research direction
Investigate how Spark implements multiple input columns for Bucketizer and StringIndexer (e.g., via inputCols parameter). Then locate the corresponding MLeap transformer implementations in the codebase, likely in the 'mleap core' module under 'transformers' package. Modify the transformer definition to accept an array of input columns and update serialization logic. Consider backward compatibility with existing single column use. Refer to existing transformers that already support multiple inputs, if any.