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https://issues.apache.org/jira/browse/MATH-1269?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Otmar Ertl updated MATH-1269:
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Attachment: MATH-1269-fix-tempC-infinity.patch
One more proposal. The problem is the calculation of (1+z)(tempA+tempB) if
tempA is infinite. In this case tempC is also infinite. If z < 0 at the same
time we get NaN for tempC*z + tempB + tempA. The proposed patch returns
infinity for the case tempC is positive infinite. In all other cases tempC*z
cannot be negative infinite and the evaluation of tempC*z + tempB + tempA is
not a problem even if tempA or tempB are positive infinite.
> FastMath.exp may return NaN for non-NaN arguments
> -------------------------------------------------
>
> Key: MATH-1269
> URL: https://issues.apache.org/jira/browse/MATH-1269
> Project: Commons Math
> Issue Type: Bug
> Affects Versions: 4.0
> Reporter: Otmar Ertl
> Attachments: MATH-1269-fix-tempC-infinity.patch, MATH-1269.patch,
> MATH-1269.patch, MATH-1269_fix_z.patch
>
>
> I have observed that FastMath.exp(709.8125) returns NaN. However, the
> exponential function must never return NaN (if the argument is not NaN). The
> result must always be non-negative or positive infinity.
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