let box = [|
    "North"; "North by east"; "North-northeast"; "Northeast by north";
    "Northeast"; "Northeast by east"; "East-northeast"; "East by north";
    "East"; "East by south"; "East-southeast"; "Southeast by east";
    "Southeast"; "Southeast by south"; "South-southeast"; "South by east";
    "South"; "South by west"; "South-southwest"; "Southwest by south";
    "Southwest"; "Southwest by west"; "West-southwest"; "West by south";
    "West"; "West by north"; "West-northwest"; "Northwest by west";
    "Northwest"; "Northwest by north"; "North-northwest"; "North by west" |]

[ 0.0; 16.87; 16.88; 33.75; 50.62; 50.63; 67.5; 84.37; 84.38;
101.25; 118.12; 118.13; 135.0; 151.87; 151.88; 168.75; 185.62;
185.63; 202.5; 219.37; 219.38; 236.25; 253.12; 253.13; 270.0;
286.87; 286.88; 303.75; 320.62; 320.63; 337.5; 354.37; 354.38 ]
|> List.iter (fun phi ->
    let i =  (int (phi * 32. / 360. + 0.5)) % 32
    printf "%3d %18s %6.2f°\n" (i + 1) box.[i] phi)