How can I find the smallest difference between two angles around a point?

by

This gives a signed angle for any angles:

a = targetA - sourceA
a = (a + 180) % 360 - 180

Beware in many languages the modulo operation returns a value with the same sign as the dividend (like C, C++, C#, JavaScript, full list here). This requires a custom mod function like so:

mod = (a, n) -> a - floor(a/n) * n

Or so:

mod = (a, n) -> (a % n + n) % n

If angles are within [-180, 180] this also works:

a = targetA - sourceA
a += (a>180) ? -360 : (a<-180) ? 360 : 0

In a more verbose way:

a = targetA - sourceA
a -= 360 if a > 180
a += 360 if a < -180

More Related Contents:

  1. How can I find the difference between two angles?
  2. Shortest distance between a point and a line segment
  3. Shortest distance between two line segments
  4. How to calculate distance from a point to a line segment, on a sphere?
  5. What’s the difference between passing by reference vs. passing by value?
  6. What’s your most controversial programming opinion?
  7. What is a callback function?
  8. Is a GUID unique 100% of the time?
  9. Algorithm for finding the fewest rectangles to cover a set of rectangles without overlapping
  10. What’s your favorite “programmer” cartoon?
  11. Code Golf: Number to Words
  12. What is name mangling, and how does it work?
  13. Given an integer, how do I find the next largest power of two using bit-twiddling?
  14. What’s the point of OOP?
  15. What is an integer overflow error?
  16. What are the advantages of memory-mapped files?
  17. Why does division by zero in IEEE754 standard results in Infinite value?
  18. Is Method Overloading considered polymorphism? [closed]
  19. What is an invariant?
  20. Arguments or parameters? [duplicate]
  21. What is an ideal variable naming convention for loop variables? [closed]
  22. Should we compare floating point numbers for equality against a *relative* error?
  23. Recursion or iteration?
  24. While vs. Do While
  25. What are “magic numbers” in computer programming?
  26. Find all complete sub-graphs within a graph
  27. Code Golf: Conway’s Game of Life
  28. Why would a language NOT use Short-circuit evaluation?
  29. Finding closest match in collection of numbers [closed]
  30. Is there a known implementation of an indexed linked list?

Leave a Comment