timeAngle and sexagesimalAngle.

bjornbm · Oct 22, 2014 · 44ee2a3 · 44ee2a3
1 parent bf9e816
commit 44ee2a3
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Showing 4 changed files with 35 additions and 15 deletions.
diff --git a/Astro/Util.hs b/Astro/Util.hs
@@ -3,6 +3,7 @@
 module Astro.Util ( r_GEO  -- From Astrodynamics
                   , perfectGEO, perfectGEO'
                   , coerceUt1ToUTC, coerceUtcToUT1
+                  , timeAngle, sexagesimalAngle, dmsAngle
                   ) where
 
 import Astro.Coords
@@ -11,7 +12,8 @@ import Astro.Time
 import Astro.Time.Interop
 import Astrodynamics (r_GEO)
 import Numeric.Units.Dimensional.Prelude
-import Numeric.Units.Dimensional.LinearAlgebra -- (fromTuple)
+import Numeric.Units.Dimensional.NonSI (revolution)
+import Numeric.Units.Dimensional.LinearAlgebra
 
 import Data.Time.Clock
 import Data.Time.Clock.TAI
@@ -46,3 +48,25 @@ coerceUt1ToUTC (E t) = taiToUTCTime (const 0) $ toAbsoluteTime (E t)
 coerceUtcToUT1 :: RealFloat a => UTCTime -> E UT1 a
 coerceUtcToUT1 = coerce . fromAbsoluteTime . utcToTAITime (const 0)
   where coerce (E t) = E t
+
+
+-- Angle representations
+-- ---------------------
+
+-- | @timeAngle hours minutes seconds@ interprets the given time as an
+  -- angle, where 24 h corresponds to 360°.
+timeAngle :: Floating a => a -> a -> a -> Angle a
+timeAngle h m s = h *~ hour + m *~ minute + s *~ second
+  where
+    hour   = prefix (1 Prelude./ 24) revolution
+    minute = prefix (1 Prelude./ 60) hour
+    second = prefix (1 Prelude./ 60) minute
+
+-- | @sexagesimalAngle degrees arcminutes arcseconds@ returns the
+  -- corresponding angle.
+sexagesimalAngle :: Floating a => a -> a -> a -> Angle a
+sexagesimalAngle d m s = d *~ degree + m *~ arcminute + s *~ arcsecond
+
+-- | @dmsAngle@ is a synonym for `sexagesimalAngle`.
+dmsAngle :: Floating a => a -> a -> a -> Angle a
+dmsAngle = sexagesimalAngle
diff --git a/examples/Biases.hs b/examples/Biases.hs
@@ -24,7 +24,7 @@ import Astro.Coords
 import Astro.Place
 import Astro.Place.ReferenceEllipsoid
 import Astro.Place.Topocentric
-import Astro.Util (perfectGEO, r_GEO)
+import Astro.Util (perfectGEO, r_GEO, sexagesimalAngle)
 import Numeric.Units.Dimensional.Prelude
 import Numeric.Units.Dimensional.LinearAlgebra
 import Numeric.Units.Dimensional.AD
@@ -83,7 +83,7 @@ stations =
   , station "Ashgabat" 38.14 58.37 0.134
   ]
 
-cibinong = GeodeticPlace wgs84 (negate $ 6*~degree + 26*~arcminute + 52*~arcsecond) (106*~degree + 56*~arcminute + 10*~arcsecond) _0
+cibinong = GeodeticPlace wgs84 (negate $ sexagesimalAngle 6 26 52) (sexagesimalAngle 106 56 10) _0
 
 -- | Computes sensitivities for a list of ground stations.
 -- If the SC is below the GS's horizon Nothing is returned.

diff --git a/test/Astro/Place/TestTopocentric.hs b/test/Astro/Place/TestTopocentric.hs
@@ -9,7 +9,7 @@ import Astro.Coords
 import Astro.Place
 import Astro.Place.Topocentric
 import Astro.Place.ReferenceEllipsoid
-import Astro.Util (perfectGEO)
+import Astro.Util (perfectGEO, sexagesimalAngle)
 import Test.QuickCheck
 import TestUtil
 import TestInstances
@@ -24,8 +24,8 @@ prop_va long f x = cmpE e (f cibinong $ perfectGEO $ long*~degree) (x*~degree)
   where
     e = 0.1 *~ degree
     cibinong = GeodeticPlace wgs84
-      (negate $ 6*~degree + 26*~arcminute + 52*~arcsecond)
-      (106*~degree + 56*~arcminute + 10*~arcsecond)
+      (negate $ sexagesimalAngle 6 26 52)
+      (sexagesimalAngle 106 56 10)
       (0*~meter)
 
 -- | Converting geocentric to topocentric and back should be identity function.

diff --git a/test/Astro/Time/SiderealSpec.hs b/test/Astro/Time/SiderealSpec.hs
@@ -14,6 +14,7 @@ import Numeric.Units.Dimensional.AD (diff)
 import Numeric.Units.Dimensional.NonSI (revolution)
 import qualified Prelude
 
+import Astro.Util
 import Astro.Util.Cyclic
 import Astro.Time
 import Astro.Time.Sidereal
@@ -31,11 +32,11 @@ spec_era = describe "Earth Rotation Angle (era)" $ do
 
   it "is consistent with AsA2009 on 2009-01-01" $
     (zeroTwoPi $ era $ clock' 2009 1 1 0 0 0 :: Angle D)
-    ~== 100 *~ degree + 39 *~ arcminute + 39.6557 *~ arcsecond
+    ~== sexagesimalAngle 100 39 39.6557
 
   it "is consistent with AsA2009 on 2010-01-01" $
     (zeroTwoPi $ era $ clock' 2010 1 1 0 0 0 :: Angle D)
-    ~== 100 *~ degree + 24 *~ arcminute + 34.2022 *~ arcsecond
+    ~== sexagesimalAngle 100 24 34.2022
 
 
 spec_phi = describe "Earth's adopted mean angular velocity (phi)" $ do
@@ -48,13 +49,8 @@ spec_gmst = describe "GMST" $ do
 
   it "is consistent with AsA2009 on 2009-01-01" $
     (zeroTwoPi $ gmst' $ clock' 2009 1 1 0 0 0 :: Angle D)
-    ~== 6 *~ h + 43 *~ m + 6.3205 *~ s
+    ~== timeAngle 6 43 6.3205
 
   it "is consistent with AsA2009 on 2010-01-01" $
     (zeroTwoPi $ gmst' $ clock' 2010 1 1 0 0 0 :: Angle D)
-    ~== 6 *~ h + 42 *~ m + 9.0298 *~ s
-
-  where
-    h = prefix (1 Prelude./ 24) revolution
-    m = prefix (1 Prelude./ 60) h
-    s = prefix (1 Prelude./ 60) m
+    ~== timeAngle 6 42 9.0298