Merge pull request #1 from michaelwp/fix-formula

fix formula
michaelwp · Apr 19, 2021 · 2f5d2b5 · 2f5d2b5
2 parents 7854175 + db49997
commit 2f5d2b5
Show file tree

Hide file tree

Showing 2 changed files with 18 additions and 3 deletions.
diff --git a/go_distance.go b/go_distance.go
@@ -3,7 +3,7 @@ package go_distance
 import "math"
 
 func (l LatLon) Count() Miles {
-	var theta = l.LatStart - l.LatEnd
+	var theta = l.LonStart - l.LonEnd
 
 	var dist = math.Sin(Degree(l.LatStart).ToRadians().ToFloat64())*
 		math.Sin(Degree(l.LatEnd).ToRadians().ToFloat64()) +
@@ -19,6 +19,21 @@ func (l LatLon) Count() Miles {
 	return Miles(miles)
 }
 
+//func (l LatLon) Count() Miles {
+//	var earthRadiusMiles = 3.958
+//
+//	var dLat = Degree(l.LatEnd - l.LatStart).ToRadians().ToFloat64()
+//	var dLon = Degree(l.LonEnd - l.LatStart).ToRadians().ToFloat64()
+//
+//	l.LatStart = Degree(l.LatStart).ToRadians().ToFloat64()
+//	l.LatEnd = Degree(l.LatEnd).ToRadians().ToFloat64()
+//
+//	var a = math.Sin(dLat/2) * math.Sin(dLat/2) +
+//		math.Sin(dLon/2)*math.Sin(dLon/2)*math.Cos(l.LatStart)*math.Cos(l.LatEnd)
+//	var c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a))
+//	return earthRadiusMiles * c
+//}
+
 func (deg Degree) ToRadians() Radian {
 	return Radian(float64(deg) * (math.Pi / 180.0))
 }

diff --git a/go_distance_test.go b/go_distance_test.go
@@ -70,7 +70,7 @@ func TestLatLon_count(t *testing.T) {
 			LonStart: 106.6388177,
 			LatEnd:   -6.3027637,
 			LonEnd:   106.6410986,
-		}, 0.5238991320272929},
+		}, 0.40323836641733635},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
@@ -94,7 +94,7 @@ func TestMiles_Kilometre(t *testing.T) {
 		want Kilometre
 	}{
 		{"Miles To Kilometres",
-			0.5238991320272929, 0.8431339247333317},
+			0.40323836641733635, 0.6489492455635418},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {