Angle difference between two bearings: Difference between revisions

Content added Content deleted
m (→‎JS ES6: Layout, function name)
m (→‎{{header|Haskell}}: (layout, function name, narrowed import))
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=={{header|Haskell}}==
=={{header|Haskell}}==
⚫
<lang Haskell>import Text.Printf (printf)

⚫
<lang Haskell>import Text.Printf


type Radians = Float
type Radians = Float
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angleBetweenDegrees :: Degrees -> Degrees -> Degrees
angleBetweenDegrees :: Degrees -> Degrees -> Degrees
angleBetweenDegrees a b = degrees $ relBearing (radians a) (radians b)
angleBetweenDegrees a b = degrees $ bearingDelta (radians a) (radians b)


relBearing :: Radians -> Radians -> Radians
bearingDelta :: Radians -> Radians -> Radians
relBearing a b -- sign * dot-product
bearingDelta a b -- sign * dot-product
= sign * acos ((ax * bx) + (ay * by))
= sign * acos ((ax * bx) + (ay * by))
where
where
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radians = (/ 180) . (pi *)
radians = (/ 180) . (pi *)


-- TEST -----------------------------------------------------------------------
main :: IO ()
main :: IO ()
main =
main =
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displayRow (x, y) =
displayRow (x, y) =
printf "%6.2f° + %6.2f° -> %7.2f°" x y $ angleBetweenDegrees x y</lang>
printf "%6.2f° + %6.2f° -> %7.2f°" x y $ angleBetweenDegrees x y</lang>

{{Out}}
{{Out}}
<pre> 20.00° + 45.00° -> 25.00°
<pre> 20.00° + 45.00° -> 25.00°
Retrieved from "https://rosettacode.org/wiki/Angle_difference_between_two_bearings"