Merge pull request #130 from observerly/feature/dusk/BelowObserversHo…

…rizon

feat: Added checks for BelowObserversHorizon() to altitude related utilities.

coverage.txt

@@ -1,8 +1,4 @@
 mode: atomic
-github.com/observerly/dusk/pkg/dusk/astrometry.go:14.52,18.12 2 16490
-github.com/observerly/dusk/pkg/dusk/astrometry.go:22.2,22.11 1 16490
-github.com/observerly/dusk/pkg/dusk/astrometry.go:18.12,20.3 1 3388
-github.com/observerly/dusk/pkg/dusk/astrometry.go:34.73,42.2 4 4
 github.com/observerly/dusk/pkg/dusk/coordinates.go:101.108,124.2 10 12982
 github.com/observerly/dusk/pkg/dusk/coordinates.go:136.149,151.2 6 16488
 github.com/observerly/dusk/pkg/dusk/lawrence.go:15.59,24.12 3 3
@@ -85,36 +81,10 @@ github.com/observerly/dusk/pkg/dusk/trigonometry.go:26.31,28.2 1 42489
 github.com/observerly/dusk/pkg/dusk/trigonometry.go:30.31,32.2 1 16543
 github.com/observerly/dusk/pkg/dusk/trigonometry.go:34.31,36.2 1 1
 github.com/observerly/dusk/pkg/dusk/trigonometry.go:38.36,40.2 1 25976
-github.com/observerly/dusk/pkg/dusk/epoch.go:31.56,33.2 1 26
-github.com/observerly/dusk/pkg/dusk/epoch.go:41.48,46.2 2 124040
-github.com/observerly/dusk/pkg/dusk/epoch.go:53.45,55.2 1 79
-github.com/observerly/dusk/pkg/dusk/epoch.go:63.60,93.13 15 16493
-github.com/observerly/dusk/pkg/dusk/epoch.go:97.2,97.12 1 16493
-github.com/observerly/dusk/pkg/dusk/epoch.go:93.13,95.3 1 5505
-github.com/observerly/dusk/pkg/dusk/epoch.go:106.74,114.11 4 16491
-github.com/observerly/dusk/pkg/dusk/epoch.go:118.2,118.17 1 16491
-github.com/observerly/dusk/pkg/dusk/epoch.go:114.11,116.3 1 0
-github.com/observerly/dusk/pkg/dusk/epoch.go:127.65,138.2 4 36
-github.com/observerly/dusk/pkg/dusk/epoch.go:146.76,154.2 3 77943
-github.com/observerly/dusk/pkg/dusk/epoch.go:162.73,170.2 3 13017
-github.com/observerly/dusk/pkg/dusk/epoch.go:179.62,190.2 3 6
-github.com/observerly/dusk/pkg/dusk/epoch.go:198.73,213.12 6 4
-github.com/observerly/dusk/pkg/dusk/epoch.go:217.2,217.11 1 4
-github.com/observerly/dusk/pkg/dusk/epoch.go:213.12,215.3 1 4
-github.com/observerly/dusk/pkg/dusk/epoch.go:226.77,248.12 10 3
-github.com/observerly/dusk/pkg/dusk/epoch.go:252.2,252.11 1 3
-github.com/observerly/dusk/pkg/dusk/epoch.go:248.12,250.3 1 0
-github.com/observerly/dusk/pkg/dusk/epoch.go:262.70,267.2 2 34
-github.com/observerly/dusk/pkg/dusk/epoch.go:276.95,280.13 2 25
-github.com/observerly/dusk/pkg/dusk/epoch.go:284.2,284.12 1 25
-github.com/observerly/dusk/pkg/dusk/epoch.go:280.13,282.3 1 0
-github.com/observerly/dusk/pkg/dusk/epoch.go:294.92,312.12 9 25
-github.com/observerly/dusk/pkg/dusk/epoch.go:317.2,317.13 1 25
-github.com/observerly/dusk/pkg/dusk/epoch.go:321.2,324.11 2 25
-github.com/observerly/dusk/pkg/dusk/epoch.go:328.2,328.21 1 25
-github.com/observerly/dusk/pkg/dusk/epoch.go:312.12,314.3 1 25
-github.com/observerly/dusk/pkg/dusk/epoch.go:317.13,319.3 1 0
-github.com/observerly/dusk/pkg/dusk/epoch.go:324.11,326.3 1 1
+github.com/observerly/dusk/pkg/dusk/astrometry.go:14.52,18.12 2 16490
+github.com/observerly/dusk/pkg/dusk/astrometry.go:22.2,22.11 1 16490
+github.com/observerly/dusk/pkg/dusk/astrometry.go:18.12,20.3 1 3388
+github.com/observerly/dusk/pkg/dusk/astrometry.go:34.73,42.2 4 4
 github.com/observerly/dusk/pkg/dusk/lunar.go:32.47,37.11 2 13006
 github.com/observerly/dusk/pkg/dusk/lunar.go:41.2,41.10 1 13006
 github.com/observerly/dusk/pkg/dusk/lunar.go:37.11,39.3 1 16
@@ -206,6 +176,42 @@ github.com/observerly/dusk/pkg/dusk/utils.go:31.12,33.3 1 0
 github.com/observerly/dusk/pkg/dusk/utils.go:47.84,49.2 1 4
 github.com/observerly/dusk/pkg/dusk/utils.go:60.84,62.2 1 12986
 github.com/observerly/dusk/pkg/dusk/utils.go:72.85,74.2 1 25
-github.com/observerly/dusk/pkg/dusk/utils.go:83.57,85.2 1 2
-github.com/observerly/dusk/pkg/dusk/utils.go:93.51,95.2 1 3
-github.com/observerly/dusk/pkg/dusk/utils.go:103.52,106.2 2 1
+github.com/observerly/dusk/pkg/dusk/utils.go:83.58,84.18 1 3
+github.com/observerly/dusk/pkg/dusk/utils.go:88.2,90.11 2 2
+github.com/observerly/dusk/pkg/dusk/utils.go:84.18,86.3 1 1
+github.com/observerly/dusk/pkg/dusk/utils.go:99.52,100.18 1 4
+github.com/observerly/dusk/pkg/dusk/utils.go:104.2,106.11 2 3
+github.com/observerly/dusk/pkg/dusk/utils.go:100.18,102.3 1 1
+github.com/observerly/dusk/pkg/dusk/utils.go:115.53,116.18 1 2
+github.com/observerly/dusk/pkg/dusk/utils.go:120.2,124.13 3 1
+github.com/observerly/dusk/pkg/dusk/utils.go:116.18,118.3 1 1
+github.com/observerly/dusk/pkg/dusk/epoch.go:31.56,33.2 1 26
+github.com/observerly/dusk/pkg/dusk/epoch.go:41.48,46.2 2 124040
+github.com/observerly/dusk/pkg/dusk/epoch.go:53.45,55.2 1 79
+github.com/observerly/dusk/pkg/dusk/epoch.go:63.60,93.13 15 16493
+github.com/observerly/dusk/pkg/dusk/epoch.go:97.2,97.12 1 16493
+github.com/observerly/dusk/pkg/dusk/epoch.go:93.13,95.3 1 5505
+github.com/observerly/dusk/pkg/dusk/epoch.go:106.74,114.11 4 16491
+github.com/observerly/dusk/pkg/dusk/epoch.go:118.2,118.17 1 16491
+github.com/observerly/dusk/pkg/dusk/epoch.go:114.11,116.3 1 0
+github.com/observerly/dusk/pkg/dusk/epoch.go:127.65,138.2 4 36
+github.com/observerly/dusk/pkg/dusk/epoch.go:146.76,154.2 3 77943
+github.com/observerly/dusk/pkg/dusk/epoch.go:162.73,170.2 3 13017
+github.com/observerly/dusk/pkg/dusk/epoch.go:179.62,190.2 3 6
+github.com/observerly/dusk/pkg/dusk/epoch.go:198.73,213.12 6 4
+github.com/observerly/dusk/pkg/dusk/epoch.go:217.2,217.11 1 4
+github.com/observerly/dusk/pkg/dusk/epoch.go:213.12,215.3 1 4
+github.com/observerly/dusk/pkg/dusk/epoch.go:226.77,248.12 10 3
+github.com/observerly/dusk/pkg/dusk/epoch.go:252.2,252.11 1 3
+github.com/observerly/dusk/pkg/dusk/epoch.go:248.12,250.3 1 0
+github.com/observerly/dusk/pkg/dusk/epoch.go:262.70,267.2 2 34
+github.com/observerly/dusk/pkg/dusk/epoch.go:276.95,280.13 2 25
+github.com/observerly/dusk/pkg/dusk/epoch.go:284.2,284.12 1 25
+github.com/observerly/dusk/pkg/dusk/epoch.go:280.13,282.3 1 0
+github.com/observerly/dusk/pkg/dusk/epoch.go:294.92,312.12 9 25
+github.com/observerly/dusk/pkg/dusk/epoch.go:317.2,317.13 1 25
+github.com/observerly/dusk/pkg/dusk/epoch.go:321.2,324.11 2 25
+github.com/observerly/dusk/pkg/dusk/epoch.go:328.2,328.21 1 25
+github.com/observerly/dusk/pkg/dusk/epoch.go:312.12,314.3 1 25
+github.com/observerly/dusk/pkg/dusk/epoch.go:317.13,319.3 1 0
+github.com/observerly/dusk/pkg/dusk/epoch.go:324.11,326.3 1 1

pkg/dusk/utils.go

@@ -80,8 +80,14 @@ func GetArgumentOfLocalSiderealTimeForTransit(latitude float64, δ float64) floa
 	@returns the atmospheric refraction in degrees for all angles from 0° - 90°
 	@see p.106 of Meeus, Jean. 1991. Astronomical algorithms. Richmond, Va: Willmann-Bell.
 */
-func GetAtmosphericRefraction(altitude float64) float64 {
-	return (1.02 / tanx(altitude+(10.3/(altitude+5.11)))) / 60
+func GetAtmosphericRefraction(altitude float64) *float64 {
+	if altitude < 0 {
+		return nil
+	}
+
+	R := (1.02 / tanx(altitude+(10.3/(altitude+5.11)))) / 60
+
+	return &R
 }
 
 /*
@@ -90,8 +96,14 @@ func GetAtmosphericRefraction(altitude float64) float64 {
 	@param altitude - is the altitude of the object in degrees
 	@returns the relative air mass, the ratio of absolute air masses (as defined above) at oblique incidence relative to that at zenith.
 */
-func GetRelativeAirMass(altitude float64) float64 {
-	return 1 / sinx(altitude+(244/(165+47*math.Pow(altitude, 1.1))))
+func GetRelativeAirMass(altitude float64) *float64 {
+	if altitude < 0 {
+		return nil
+	}
+
+	X := 1 / sinx(altitude+(244/(165+47*math.Pow(altitude, 1.1))))
+
+	return &X
 }
 
 /*
@@ -100,7 +112,14 @@ func GetRelativeAirMass(altitude float64) float64 {
 	@param altitude - is the altitude of the object in degrees
 	@returns the apparent altitude in degrees
 */
-func GetApparentAltitude(altitude float64) float64 {
+func GetApparentAltitude(altitude float64) *float64 {
+	if altitude < 0 {
+		return nil
+	}
+
 	R := GetAtmosphericRefraction(altitude)
-	return altitude + R
+
+	app := altitude + *R
+
+	return &app
 }

pkg/dusk/utils_test.go

@@ -99,69 +99,93 @@ func TestGetArgumentOfLocalSiderealTime(t *testing.T) {
 func TestGetAtmosphericRefraction(t *testing.T) {
 	var hz HorizontalCoordinate = ConvertEquatorialCoordinateToHorizontal(datetime, longitude, latitude, EquatorialCoordinate{RightAscension: 88.7929583, Declination: 7.4070639})
 
-	var got float64 = GetAtmosphericRefraction(hz.Altitude)
+	got := GetAtmosphericRefraction(hz.Altitude)
 
 	var want float64 = 0.005219
 
-	if math.Abs(got-want) > 0.00001 {
-		t.Errorf("got %f, wanted %f", got, want)
+	if math.Abs(*got-want) > 0.00001 {
+		t.Errorf("got %f, wanted %f", *got, want)
 	}
 
-	if got < 0 || got > 1.0 {
+	if *got < 0 || *got > 1.0 {
 		t.Errorf("The atmospheric refraction must be between 0.0 and 0.5")
 	}
 }
 
+func TestGetAtmosphericRefractionBelowHorizon(t *testing.T) {
+	got := GetAtmosphericRefraction(-45)
+
+	if got != nil {
+		t.Errorf("The atmospheric refraction must be nil below the observer's horizon")
+	}
+}
+
 func TestGetRelativeAirMass(t *testing.T) {
 	var hz HorizontalCoordinate = ConvertEquatorialCoordinateToHorizontal(datetime, longitude, latitude, EquatorialCoordinate{RightAscension: 88.7929583, Declination: 7.4070639})
 
-	var got float64 = GetRelativeAirMass(hz.Altitude)
+	got := GetRelativeAirMass(hz.Altitude)
 
 	var want float64 = 1.046558
 
-	if math.Abs(got-want) > 0.00001 {
-		t.Errorf("got %f, wanted %f", got, want)
+	if math.Abs(*got-want) > 0.00001 {
+		t.Errorf("got %f, wanted %f", *got, want)
 	}
 
-	if got < 1 || got > 40.0 {
+	if *got < 1 || *got > 40.0 {
 		t.Errorf("The relative air mass must be a value bewteen 1 and approx. 40 at the observer's horizon")
 	}
 }
 
 func TestGetRelativeAirMassAtZenith(t *testing.T) {
-	var got float64 = GetRelativeAirMass(90)
+	got := GetRelativeAirMass(90)
 
 	var want float64 = 1.0
 
-	if math.Abs(got-want) > 0.00001 {
-		t.Errorf("got %f, wanted %f", got, want)
+	if math.Abs(*got-want) > 0.00001 {
+		t.Errorf("got %f, wanted %f", *got, want)
 	}
 
-	if got < 1 || got > 40.0 {
+	if *got < 1 || *got > 40.0 {
 		t.Errorf("The relative air mass must be a value bewteen 1 and approx. 40 at the observer's horizon")
 	}
 }
 
 func TestGetRelativeAirMassAtHorizon(t *testing.T) {
-	var got float64 = GetRelativeAirMass(0)
+	got := GetRelativeAirMass(0)
 
 	var want float64 = 38
 
-	if math.Abs(got-want) > 2 {
+	if math.Abs(*got-want) > 2 {
 		t.Errorf("The relative air mass must be approximately ~37 - 39 at the observer's horizon")
 	}
 
-	if got < 1 || got > 40.0 {
+	if *got < 1 || *got > 40.0 {
 		t.Errorf("The relative air mass must be a value bewteen 1 and approx. 40 at the observer's horizon")
 	}
 }
 
+func TestGetRelativeAirMassBelowHorizon(t *testing.T) {
+	got := GetRelativeAirMass(-1)
+
+	if got != nil {
+		t.Errorf("The relative air mass must be nil below the observer's horizon")
+	}
+}
+
 func TestGetApparentAltitude(t *testing.T) {
 	var hz HorizontalCoordinate = ConvertEquatorialCoordinateToHorizontal(datetime, longitude, latitude, EquatorialCoordinate{RightAscension: 88.7929583, Declination: 7.4070639})
 
-	var got float64 = GetApparentAltitude(hz.Altitude)
+	got := GetApparentAltitude(hz.Altitude)
+
+	if math.Abs(*got-hz.Altitude) > 0.0053 {
+		t.Errorf("got %f, wanted %f", *got, hz.Altitude)
+	}
+}
+
+func TestGetApparentAltitudeBelowHorizon(t *testing.T) {
+	got := GetApparentAltitude(-45)
 
-	if math.Abs(got-hz.Altitude) > 0.0053 {
-		t.Errorf("got %f, wanted %f", got, hz.Altitude)
+	if got != nil {
+		t.Errorf("The apparent altitude must have no adjustment below the observer's horizon")
 	}
 }