DM-9765: Suspicious numerical precision code in Angle #237
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kfindeisen
approved these changes
May 24, 2017
| if (wrapped - refAngRad < -PI) { | ||
| wrapped -= wrapped * 2.0 * std::numeric_limits<double>::epsilon(); | ||
| wrapped += TWOPI; |
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While this is certainly cleaner, I do wonder why the original code didn't use TWOPI here when it did everywhere else.
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Because the original code tried to keep within bounds at both ends in radians. By adding 2 pi the result may put wrapped - refAngRad >= 2 pi. Still, I'm inclined to live with that. The limits are squishy for other units anyway and we have no use case for precise limits. I will update the docs for wrapNear. Also the test needs some work to exercise cases where the upper limit is violated.
A test for the result of Angle.wrapNear being too small applied the incorrect correction when the wrapped result was positive. Added a test that shows the problem (it was not easy to trigger, but setting wrapRef to 5 did the trick). Adding wrapRef caused indentation to be so deep that I switched to using itertools.product to tame it.
instead of adding a small value if the lower limit is exceeded, add 2 pi. This simplies the code and gives better accuracy.
Use more specific asserts where useful. Remove unneeded checks of angle != None. Remove useless print statements.
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