[MAHOUT-268] Vector.getDistanceSquared() is incorrect for both SparseVector varieties

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.2
• Fix Version/s: 0.3

Environment

all

• Assignee: Jake Mannix
• Reporter: jakes old (non-committer) account
• Created: 27/Jan/10 07:48
• Updated: 21/May/11 03:23
• Resolved: 28/Jan/10 06:13

Description

I'm pretty sure that getDistanceSquared() should just return as if an optimized implementation of:

  public double getDistanceSquared(Vector v) { return this.minus(v).getLengthSquared(); }

In which case if some vector elements are negative, both SequentialAccessSparseVector (my fault!) and RandomAccessSparseVector return the wrong thing. Very easy to write a failing unit test for this one.