June 2018 Update

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