June 2018 Update

Task/Averages-Mean-angle/JavaScript/averages-mean-angle.js

@@ -1,18 +1,21 @@
 function sum(a) {
-    s = 0;
-    for (var i in a) s += a[i];
+    var s = 0;
+    for (var i = 0; i < a.length; i++) s += a[i];
     return s;
 }
 
 function degToRad(a) {
-    return Math.PI/180*a;
+    return Math.PI / 180 * a;
 }
 
 function meanAngleDeg(a) {
-    return 180/Math.PI*Math.atan2(sum(a.map(degToRad).map(Math.sin))/a.length,sum(a.map(degToRad).map(Math.cos))/a.length);
+    return 180 / Math.PI * Math.atan2(
+        sum(a.map(degToRad).map(Math.sin)) / a.length,
+        sum(a.map(degToRad).map(Math.cos)) / a.length
+    );
 }
 
-var a = [350, 10], b = [90, 180, 270, 360],  c =[10, 20, 30];
+var a = [350, 10], b = [90, 180, 270, 360],  c = [10, 20, 30];
 console.log(meanAngleDeg(a));
 console.log(meanAngleDeg(b));
 console.log(meanAngleDeg(c));

Task/Averages-Mean-angle/Ring/averages-mean-angle.ring

@@ -0,0 +1,37 @@
+# Project : Averages/Mean angle
+# Date    : 2018/01/08
+# Author : Gal Zsolt (~ CalmoSoft ~)
+# Email   : <calmosoft@gmail.com>
+
+load "stdlib.ring"
+decimals(6)
+pi = 3.1415926535897
+angles = [350,10]
+see meanangle(angles, len(angles)) + nl
+angles = [90,180,270,360]
+see meanangle(angles, len(angles)) + nl
+angles = [10,20,30]
+see meanangle(angles, len(angles)) + nl
+
+func meanangle(angles, n)
+        sumsin = 0
+        sumcos = 0
+        for i = 1 to n
+             sumsin = sumsin + sin(angles[i]*pi/180)
+             sumcos = sumcos + cos(angles[i]*pi/180)
+        next
+        return 180/pi*atan3(sumsin, sumcos)
+
+func atan3(y,x)
+        if x <= 0
+           return sign(y)*pi/2
+        ok
+        if x>0
+           return atan(y/x)
+        else
+           if y>0
+              return atan(y/x)+pi
+           else
+              return atan(y/x)-pi
+           ok
+        ok

Task/Averages-Mean-angle/Stata/averages-mean-angle.stata

@@ -1,9 +1,9 @@
 mata
 function meanangle(a) {
-return(arg(sum(exp(C(0,a)))))
+	return(arg(sum(exp(C(0,a)))))
 }
 
-deg=acos(-1)/180
+deg=pi()/180
 
 meanangle((350,10)*deg)/deg
   -1.61481e-15