Data.Geo.Jord.Angle

Types and functions for working with angles representing latitudes, longitude and bearings.

In order to use this module you should start with the following imports:

import Data.Geo.Jord.Angle (Angle)
import qualified Data.Geo.Jord.Angle as Angle

The Angle type

data Angle

An angle with a resolution of a microarcsecond. When used as a latitude/longitude this roughly translate to a precision of 0.03 millimetres at the equator.

Instances

Eq Angle

Defined in Data.Geo.Jord.Angle

Methods

(==) :: Angle -> Angle -> Bool

(/=) :: Angle -> Angle -> Bool

Ord Angle

Defined in Data.Geo.Jord.Angle

Methods

compare :: Angle -> Angle -> Ordering

(<) :: Angle -> Angle -> Bool

(<=) :: Angle -> Angle -> Bool

(>) :: Angle -> Angle -> Bool

(>=) :: Angle -> Angle -> Bool

max :: Angle -> Angle -> Angle

min :: Angle -> Angle -> Angle

Read Angle

See angle.

Defined in Data.Geo.Jord.Angle

Methods

readsPrec :: Int -> ReadS Angle

readList :: ReadS [Angle]

readPrec :: ReadPrec Angle

readListPrec :: ReadPrec [Angle]

Show Angle

Show Angle as degrees, minutes, seconds and milliseconds - e.g. 154°25'43.5".

Defined in Data.Geo.Jord.Angle

Methods

showsPrec :: Int -> Angle -> ShowS

show :: Angle -> String

showList :: [Angle] -> ShowS

Smart constructors

decimalDegrees :: Double -> Angle

Angle from given decimal degrees. Any Double is accepted: it must be validated by the call site when representing a latitude or longitude.

dms :: Int -> Int -> Double -> Either String Angle

Angle from the given degrees, arcminutes and decimal arcseconds. A Left indicates that given arcminutes and/or arcseconds are invalid.

radians :: Double -> Angle

Angle from the given radians.

Calculations

arcLength :: Angle -> Length -> Length

arcLength a r computes the Length of the arc that subtends the angle a for radius r.

central :: Length -> Length -> Angle

central l r computes the central Angle from the arc length l and radius r.

clockwiseDifference :: Angle -> Angle -> Angle

clockwiseDifference f s computes the angle between given angles, rotating clockwise.

isNegative :: Angle -> Bool

Is given Angle < 0?

isWithin :: Angle -> Angle -> Angle -> Bool

Is given Angle within range [low..high] inclusive?

negate :: Angle -> Angle

Returns the given Angle negated.

normalise :: Angle -> Angle -> Angle

normalise a n normalises a to [0, n].

Trigonometric functions

asin :: Double -> Angle

asin a computes arc sine of a.

atan2 :: Double -> Double -> Angle

atan2 y x computes the Angle (from the positive x-axis) of the vector from the origin to the point (x,y).

cos :: Angle -> Double

cos a returns the cosinus of a.

sin :: Angle -> Double

sin a returns the sinus of a.

Accessors

getDegrees :: Angle -> Int

getDegrees a returns the degree component of a.

getArcminutes :: Angle -> Int

getArcminutes a returns the arcminute component of a.

getArcseconds :: Angle -> Int

getArcseconds a returns the arcsecond component of a.

getArcmilliseconds :: Angle -> Int

getArcmilliseconds a returns the arcmilliseconds component of a.

Conversions

toDecimalDegrees :: Angle -> Double

Converts the given Angle to decimal degrees.

toRadians :: Angle -> Double

degrees to radians.

Read

angle :: ReadP Angle

Parses and returns an Angle.

Supported formats:

• d°m′s.ms″ - e.g. 55°36'21.3", where minutes, seconds and milliseconds are optional.
• decimal° - e.g. 55.6050° or -133°

Symbols:

• degree: ° or d
• minute: ', ′ or m
• second: ", ″, '' or s

read :: String -> Maybe Angle

Reads an Angle from the given string using angle.

Misc

add :: Angle -> Angle -> Angle

Adds 2 angles.

subtract :: Angle -> Angle -> Angle

Subtracts 2 angles.

zero :: Angle

0 degrees.