[HAMA-668] Fix possible number instabilities in LogisticRegression CF

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.6.0
• Component/s: machine learning
• Assignee: Tommaso Teofili
• Reporter: Tommaso Teofili
• Created: 09/Nov/12 10:26
• Updated: 22/Nov/12 00:05
• Resolved: 21/Nov/12 09:43

Description

In calculateCostForItem the log of several calculations may run in the special cases of the logarithm:

• If the argument is NaN or less than zero, then the result is NaN.
• If the argument is positive infinity, then the result is positive infinity.
• If the argument is positive zero or negative zero, then the result is negative infinity.
  We should guard them.