Box the compass

Avast me hearties!

Box the compass is a draft programming task. It is not yet considered ready to be promoted as a complete task, for reasons that should be found in its talk page.

There be many a land lubber that knows naught of the pirate ways and gives direction by degree! They know not how to box the compass!

Task description

1. Create a function that takes a heading in degrees and returns the correct 32-point compass heading.
2. Print and display a table of Index, Compass point, and Degree; rather like the corresponding columns from, the first table of the wikipedia article, but use the following 33 headings as input:

[0.0, 16.87, 28.12, 33.75, 50.62, 61.87, 67.5, 84.37, 95.62, 101.25, 118.12, 129.37, 135.0, 151.87, 163.12, 168.75, 185.62, 196.87, 202.5, 219.37, 230.62, 236.25, 253.12, 264.37, 270.0, 286.87, 298.12, 303.75, 320.62, 331.87, 337.5, 354.37, 365.62]. (They should give the same order of points but are spread throughout the ranges of acceptance).

Python

<lang python>majors = 'north east south west'.split() majors = majors + majors # no need for module later quarter1 = 'N,N by E,N-NE,NE by N,NE,NE by E,E-NE,E by N'.split(',') quarter2 = [p.replace('NE','EN') for p in quarter1]

def degrees2compasspoint(d):

   d = (d % 360) + 360/64
   if d < 0:
       d += 360
   majorindex, minor = divmod(d, 90.)
   majorindex = int(majorindex)
   minorindex  = int( (minor*4) // 45 )
   p1, p2 = majors[majorindex: majorindex+2]
   if p1 in {'north', 'south'}:
       q = quarter1
   else:
       q = quarter2
   return q[minorindex].replace('N', p1).replace('E', p2).capitalize()

for i in range(33):

   d = i * 11.25
   m = i % 3
   if   m == 1: d += 5.62
   elif m == 2: d -= 5.62
   n = i % 32 + 1
   print( '%2i %-18s %7.2f°' % (n, degrees2compasspoint(d), d) )</lang>

Output

 1 North                 0.00°
 2 North by east        16.87°
 3 North-northeast      16.88°
 4 Northeast by north   33.75°
 5 Northeast            50.62°
 6 Northeast by east    50.63°
 7 East-northeast       67.50°
 8 East by north        84.37°
 9 East                 84.38°
10 East by south       101.25°
11 East-southeast      118.12°
12 Southeast by east   118.13°
13 Southeast           135.00°
14 Southeast by south  151.87°
15 South-southeast     151.88°
16 South by east       168.75°
17 South               185.62°
18 South by west       185.63°
19 South-southwest     202.50°
20 Southwest by south  219.37°
21 Southwest           219.38°
22 Southwest by west   236.25°
23 West-southwest      253.12°
24 West by south       253.13°
25 West                270.00°
26 West by north       286.87°
27 West-northwest      286.88°
28 Northwest by west   303.75°
29 Northwest           320.62°
30 Northwest by north  320.63°
31 North-northwest     337.50°
32 North by west       354.37°
 1 North               354.38°