Merge pull request #21 from darkskyapp/ironwallaby/fix_astro

fix sin/cos azimuth
darkskyapp · Oct 8, 2019 · aaa5153 · aaa5153
2 parents e0e33fe + f80388b
commit aaa5153
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Showing 2 changed files with 4 additions and 6 deletions.
diff --git a/lib/solar.js b/lib/solar.js
@@ -201,9 +201,7 @@ class Location {
   }
 
   get azimuth() {
-    // NOTE: This Math.PI and negative silliness is so we return 0..2π
-    // (instead of -π..π).
-    return Math.PI + Math.atan2(-this.sin_azimuth, -this.cos_azimuth);
+    return Math.atan2(this.cos_azimuth, this.sin_azimuth) + Math.PI;
   }
 }
 
@@ -248,8 +246,8 @@ class Time {
       sin_hour_angle,
       cos_hour_angle,
       _sin_elevation(sin_lat, cos_lat, sin_dec, cos_dec, cos_hour_angle),
-      -sin_hour_angle,
-      -(cos_hour_angle * sin_lat - tan_dec * cos_lat)
+      cos_hour_angle * sin_lat - tan_dec * cos_lat,
+      sin_hour_angle
     );
   }
 }

diff --git a/package.json b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "astro",
-  "version": "2.2.3",
+  "version": "2.2.4",
   "description": "Solar and lunar position calculations",
   "main": "index.js",
   "devDependencies": {