fix(trigonometry): add arctan2() function#114
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antfullstack merged 1 commit intoantfullstack:mainfrom Apr 12, 2026
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Implement arctan2(y, x) — the two-argument arctangent — in trigonometry.py. Unlike arctan(y/x), arctan2 handles all four quadrants correctly by inspecting the signs of both arguments: - x > 0 → arctan(y/x) - x < 0, y ≥ 0 → arctan(y/x) + π - x < 0, y < 0 → arctan(y/x) − π - x = 0, y > 0 → π/2 - x = 0, y < 0 → −π/2 - x = 0, y = 0 → 0.0 (matches math.atan2 behaviour) Return value is in the range (−π, π], consistent with the standard two-argument arctangent convention.
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Very nice implementation and docstring comments, good job! |
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Problem
Issue #112 requested an
arctan2()function intrigonometry.py. The standardarctan(y/x)only gives results in the range (−π/2, π/2) and loses quadrant information;arctan2(y, x)correctly maps any (x, y) point to an angle in (−π, π].Solution
Implemented
arctan2(y, x)using quadrant-aware case analysis over the signs ofxandy, delegating to the existingarctan()function:Files Changed
simple_equ/geometry/trigonometry.py— addedarctan2()function with full docstringVerification
All quadrants tested against
math.atan2— results match to 1e-9 precision.Closes #112