Data.Geo.Jord.Angle

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

The Angle type

data Angle

An angle with a resolution of a milliseconds of a degree. When used as a latitude/longitude this roughly translate to a precision of 30 millimetres at the equator.

Instances

Eq Angle

Defined in Data.Geo.Jord.Angle

Methods

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

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

Read Angle

See readAngle.

Defined in Data.Geo.Jord.Angle

Methods

readsPrec :: Int -> ReadS Angle

readList :: ReadS [Angle]

readPrec :: ReadPrec Angle

readListPrec :: ReadPrec [Angle]

Show Angle

Angle is shown 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

Quantity Angle

Add/Subtract Angle.

Defined in Data.Geo.Jord.Angle

Methods

add :: Angle -> Angle -> Angle

sub :: Angle -> Angle -> Angle

zero :: Angle

Smart constructors

decimalDegrees :: Double -> Angle

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

dms :: Int -> Int -> Int -> Int -> Angle

Angle from the given given degrees, minutes, seconds and milliseconds. errors if given minutes, seconds and/or milliseconds are invalid. Degrees are not validated and can be any Int: they must be validated by the call site when used to represent a latitude or longitude.

dmsE :: Int -> Int -> Int -> Int -> Either String Angle

Angle from the given given degrees, minutes, seconds and milliseconds. A Left indicates that given minutes, seconds and/or milliseconds are invalid. Degrees are not validated and can be any Int: they must be validated by the call site when used to represent a latitude or longitude.

dmsF :: MonadFail m => Int -> Int -> Int -> Int -> m Angle

Angle from the given given degrees, minutes, seconds and milliseconds. fails if given minutes, seconds and/or milliseconds are invalid. Degrees are not validated and can be any Int: they must be validated by the call site when used to represent a latitude or longitude.

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.

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.

getMinutes :: Angle -> Int

getMinutes a returns the minute component of a.

getSeconds :: Angle -> Int

getSeconds a returns the second component of a.

getMilliseconds :: Angle -> Int

getMilliseconds a returns the milliseconds component of a.

toDecimalDegrees :: Angle -> Double

Converts the given Angle to decimal degrees.

Read

angle :: ReadP Angle

Parses and returns an Angle.

readAngle :: String -> Angle

Obtains a Angle from the given string formatted as either:

• 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

This simply calls read s :: Angle so error should be handled at the call site.

readAngleE :: String -> Either String Angle

Same as readAngle but returns an Either.

readAngleF :: MonadFail m => String -> m Angle

Same as readAngle but returns a MonadFail.