[HIVEMALL-245] Refactor RandomForest for Sparse Data handling

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.5.2
• Fix Version/s: 0.6.0
• Assignee: Makoto Yui
• Reporter: Makoto Yui
• Created: 08/Apr/19 16:33
• Updated: 13/Sep/19 09:23
• Resolved: 13/Sep/19 09:23

Description

• Fix attribute to use RoaringBitmap instead of AttributeType[]
• Support pruning of redundant decision tree nodes
• Support the default value for missing values
• Fix split handling of sparse numeric values
  • problem: split does not occur when column values have a single value
    • if(x<=1.0) { .. } else { ... } never split where sparse x is already 1.0
  • if there are only a single value for a column, then treat it as nominal value

Issue Links

• links to: GitHub Pull Request #198