[MATH-1206] Cost in least-squares fitting

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.3, 3.4, 3.4.1
• Fix Version/s: 4.0
• Assignee: Gilles Sadowski
• Reporter: Gilles Sadowski
• Created: 26/Feb/15 13:55
• Updated: 09/Apr/15 12:39
• Resolved: 09/Apr/15 12:39

Description

In org.apache.commons.math4.fitting.leastsquares.AbstractEvaluation, the value returned by the "getCost" method is not consistent with the definition of "cost" in a least-squares problem: It is the sum of the squares of the residuals, but the method returns the square-root of that quantity.