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https://issues.apache.org/jira/browse/MATH-956?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13614107#comment-13614107
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Luc Maisonobe commented on MATH-956:
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I agree.
The reason for the difference is probably because at 1.0, the seperation
between two normal numbers change, due to exponent change. For numbers just
below 1.0, the least significant bit is twice smaller than the least
significant bit of numbers just above 1.0. Of course, similar scale changes
occur also around 0.5, 0.25, 0.125 ... on one side and around 2.0, 4.0, 8.0 ...
on the other side.
> Hardcoded numbers in "LevenbergMarquardtOptimizer"
> --------------------------------------------------
>
> Key: MATH-956
> URL: https://issues.apache.org/jira/browse/MATH-956
> Project: Commons Math
> Issue Type: Task
> Affects Versions: 3.1.1
> Reporter: Gilles
> Priority: Minor
> Fix For: 3.2
>
>
> The class contains numbers "2.2251e-308" and "2.2204e-16".
> The former is the "SAFE_MIN" defined in class "Precision".
> The latter is documented as
> {noformat}
> 2.2204e-16 is the machine epsilon for IEEE754
> {noformat}
> However, the "EPSILON" defined in class "Precision" is equal to
> "1.1102230246251565E-16" (i.e. half the above number). This requires
> clarification.
> I would remove the seemingly incorrect comment (if we assume that the correct
> definition is in the comment for "EPSILON" in "Precision") and replace the
> hard-coded values with
> {noformat}
> 2 * Precision.EPSILON
> {noformat}
> Do you agree?
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