Comments on: Fun with Math

By: marocchino

marocchino — Sat, 02 May 2009 01:44:54 +0000

how about this?

def diff_deg(a,b)
(diff=(a-b).abs)>180&&360-diff||diff
end

Derek Neighbors — Wed, 29 Apr 2009 15:54:21 +0000

Math can be fun. I would love to see the Objective-C test and the Objective-C code to compare.

Craig Buchek — Wed, 29 Apr 2009 15:13:38 +0000

I don’t see any reason to convert to radians and back to degrees. The code would be a lot simpler if you didn’t:

def diff_deg(a,b)
dif = ((a % 360) – (b % 360)).abs
dif = 360 – dif if dif > 180
dif
end

Steve Tooke — Wed, 29 Apr 2009 14:06:03 +0000

You don’t need to convert to radians and back to use the same result:

mathfan — Wed, 29 Apr 2009 11:44:20 +0000

Let thita = abs(thita1 – thita2)
answer = min{thita, 360 – thita}

Shalom Craimer — Wed, 29 Apr 2009 11:05:46 +0000

I don’t feel there was any need for converting it to radians… You just want to figure out the difference and constrain it to be below 180!

def diff_deg(a,b)
#adjust for zero
a = 360 if a == 0
b = 360 if b == 0

dif = (a-b).abs

# constrain to the shortest path, so trim if it’s > 180°
dif = (dif > 180) ? (360-dif) : dif
end