September 2017 Update

Task/Averages-Mean-angle/Haskell/averages-mean-angle-1.hs

@@ -1,6 +1,15 @@
 import Data.Complex (cis, phase)
 
+meanAngle
+  :: RealFloat c
+  => [c] -> c
 meanAngle = (/ pi) . (* 180) . phase . sum . map (cis . (/ 180) . (* pi))
 
-main = mapM_ (\angles -> putStrLn $ "The mean angle of " ++ show angles ++ " is: " ++ show (meanAngle angles) ++ " degrees")
-       [[350, 10], [90, 180, 270, 360], [10, 20, 30]]
+main :: IO ()
+main =
+  mapM_
+    (\angles ->
+        putStrLn $
+        "The mean angle of " ++
+        show angles ++ " is: " ++ show (meanAngle angles) ++ " degrees")
+    [[350, 10], [90, 180, 270, 360], [10, 20, 30]]

Task/Averages-Mean-angle/Java/averages-mean-angle.java

@@ -1,60 +1,30 @@
-import java.util.ArrayList;
 import java.util.Arrays;
-import java.util.List;
 
-public class RAvgMeanAngle {
+public class AverageMeanAngle {
 
-  private static final List<List<Double>> samples;
-
-  static {
-    samples = new ArrayList<>();
-    samples.add(Arrays.asList(350.0, 10.0));
-    samples.add(Arrays.asList(90.0, 180.0, 270.0, 360.0));
-    samples.add(Arrays.asList(10.0, 20.0, 30.0));
-    samples.add(Arrays.asList(370.0));
-    samples.add(Arrays.asList(180.0));
-  }
-
-  public RAvgMeanAngle() {
-
-    return;
-  }
-
-  public double getMeanAngle(List<Double> sample) {
-
-    double x_component = 0.0;
-    double y_component = 0.0;
-    double avg_d, avg_r;
-
-    for (double angle_d : sample) {
-      double angle_r;
-      angle_r = Math.toRadians(angle_d);
-      x_component += Math.cos(angle_r);
-      y_component += Math.sin(angle_r);
-    }
-    x_component /= sample.size();
-    y_component /= sample.size();
-    avg_r = Math.atan2(y_component, x_component);
-    avg_d = Math.toDegrees(avg_r);
-
-    return avg_d;
-  }
-
-  public static void main(String[] args) {
-
-    runSample(args);
-
-    return;
-  }
-
-  public static void runSample(String[] args) {
-
-    RAvgMeanAngle main = new RAvgMeanAngle();
-    for (List<Double> sample : samples) {
-      double meanAngle = main.getMeanAngle(sample);
-      System.out.printf("The mean angle of %s is:%n%12.6f%n%n", sample, meanAngle);
+    public static void main(String[] args) {
+        printAverageAngle(350.0, 10.0);
+        printAverageAngle(90.0, 180.0, 270.0, 360.0);
+        printAverageAngle(10.0, 20.0, 30.0);
+        printAverageAngle(370.0);
+        printAverageAngle(180.0);
     }
 
-    return;
-  }
+    private static void printAverageAngle(double... sample) {
+        double meanAngle = getMeanAngle(sample);
+        System.out.printf("The mean angle of %s is %s%n", Arrays.toString(sample), meanAngle);
+    }
+
+    public static double getMeanAngle(double... anglesDeg) {
+        double x = 0.0;
+        double y = 0.0;
+
+        for (double angleD : anglesDeg) {
+            double angleR = Math.toRadians(angleD);
+            x += Math.cos(angleR);
+            y += Math.sin(angleR);
+        }
+        double avgR = Math.atan2(y / anglesDeg.length, x / anglesDeg.length);
+        return Math.toDegrees(avgR);
+    }
 }

Task/Averages-Mean-angle/Kotlin/averages-mean-angle.kotlin

@@ -0,0 +1,17 @@
+// version 1.0.5-2
+
+fun meanAngle(angles: DoubleArray): Double {
+    val sinSum = angles.sumByDouble {  Math.sin(it * Math.PI / 180.0) }
+    val cosSum = angles.sumByDouble {  Math.cos(it * Math.PI / 180.0) }
+    return Math.atan2(sinSum / angles.size, cosSum / angles.size) * 180.0 / Math.PI
+}
+
+fun main(args: Array<String>) {
+    val angles1 = doubleArrayOf(350.0, 10.0)
+    val angles2 = doubleArrayOf(90.0, 180.0, 270.0, 360.0)
+    val angles3 = doubleArrayOf(10.0, 20.0, 30.0)
+    val fmt  = "%.2f degrees" // format results to 2 decimal places
+    println("Mean for angles 1 is ${fmt.format(meanAngle(angles1))}")
+    println("Mean for angles 2 is ${fmt.format(meanAngle(angles2))}")
+    println("Mean for angles 3 is ${fmt.format(meanAngle(angles3))}")
+}

Task/Averages-Mean-angle/Lua/averages-mean-angle.lua

@@ -1,11 +1,11 @@
 function meanAngle (angleList)
-	local sumSin, sumCos = 0, 0
-	for i, angle in pairs(angleList) do
-		sumSin = sumSin + math.sin(math.rad(angle))
-		sumCos = sumCos + math.cos(math.rad(angle))
-	end
-	local result = math.deg(math.atan2(sumSin, sumCos))
-	return string.format("%.2f", result)
+  local sumSin, sumCos = 0, 0
+  for i, angle in pairs(angleList) do
+    sumSin = sumSin + math.sin(math.rad(angle))
+    sumCos = sumCos + math.cos(math.rad(angle))
+  end
+  local result = math.deg(math.atan2(sumSin, sumCos))
+  return string.format("%.2f", result)
 end
 
 print(meanAngle({350, 10}))

Task/Averages-Mean-angle/Nim/averages-mean-angle.nim

@@ -1,12 +1,12 @@
 import math, complex
 
-proc rect(r, phi): Complex = (r * cos(phi), sin(phi))
-proc phase(c): float = arctan2(c.im, c.re)
+proc rect(r, phi: float): Complex = (r * cos(phi), sin(phi))
+proc phase(c: Complex): float = arctan2(c.im, c.re)
 
-proc radians(x): float = (x * Pi) / 180.0
-proc degrees(x): float = (x * 180.0) / Pi
+proc radians(x: float): float = (x * Pi) / 180.0
+proc degrees(x: float): float = (x * 180.0) / Pi
 
-proc meanAngle(deg): float =
+proc meanAngle(deg: openArray[float]): float =
   var c: Complex
   for d in deg:
     c += rect(1.0, radians(d))

Task/Averages-Mean-angle/OoRexx/averages-mean-angle.rexx

@@ -0,0 +1,24 @@
+/*REXX program computes the  mean angle  (angles expressed in degrees). */
+numeric digits 50                      /*use fifty digits of precision, */
+       showDig=10                      /*··· but only display 10 digits.*/
+xl = 350 10            ;      say showit(xl, meanAngleD(xl) )
+xl = 90 180 270 360    ;      say showit(xl, meanAngleD(xl) )
+xl = 10 20 30          ;      say showit(xl, meanAngleD(xl) )
+exit                                   /*stick a fork in it, we're done.*/
+/*----------------------------------MEANANGD subroutine-----------------*/
+meanAngleD:  procedure;  parse arg xl;   numeric digits digits()+digits()%4
+sum.=0
+n=words(xl)
+do j=1 to n
+  sum.0sin+=rxCalcSin(word(xl,j))
+  sum.0cos+=rxCalcCos(word(xl,j))
+  End
+If sum.0cos=0 Then
+  Return sign(sum.0sin/n)*90
+Else
+  Return rxCalcArcTan((sum.0sin/n)/(sum.0cos/n))
+
+showit: procedure expose showDig;  numeric digits showDig;  parse arg a,mA
+        return left('angles='a,30)  'mean angle='  format(mA,,showDig,0)/1
+
+::requires rxMath library;

Task/Averages-Mean-angle/PowerShell/averages-mean-angle-1.psh

@@ -0,0 +1,7 @@
+function Get-MeanAngle ([double[]]$Angles)
+{
+    $x = ($Angles | ForEach-Object {[Math]::Cos($_ * [Math]::PI / 180)} | Measure-Object -Average).Average
+    $y = ($Angles | ForEach-Object {[Math]::Sin($_ * [Math]::PI / 180)} | Measure-Object -Average).Average
+
+    [Math]::Atan2($y, $x) * 180 / [Math]::PI
+}

Task/Averages-Mean-angle/PowerShell/averages-mean-angle-2.psh

@@ -0,0 +1 @@
+@(350, 10), @(90, 180, 270, 360), @(10, 20, 30) | ForEach-Object {Get-MeanAngle $_}

Task/Averages-Mean-angle/Scheme/averages-mean-angle.ss

@@ -0,0 +1,23 @@
+(import (srfi 1 lists))  ;; use 'fold' from library
+
+(define (average l)
+  (/ (fold + 0 l) (length l)))
+
+(define pi 3.14159265358979323846264338327950288419716939937510582097)
+
+(define (radians a)
+  (* pi 1/180 a))
+
+(define (degrees a)
+  (* 180 (/ 1 pi) a))
+
+(define (mean-angle angles)
+  (let* ((angles (map radians angles))
+         (cosines (map cos angles))
+         (sines (map sin angles)))
+    (degrees (atan (average sines) (average cosines)))))
+
+(for-each (lambda (angles)
+            (display "The mean angle of ") (display angles)
+            (display " is ") (display (mean-angle angles)) (newline))
+          '((350 10) (90 180 270 360) (10 20 30)))

Task/Averages-Mean-angle/Sidef/averages-mean-angle.sidef

@@ -1,10 +1,10 @@
 func mean_angle(angles) {
-    Math.atan2(
+    atan2(
         Math.avg(angles.map{ .deg2rad.sin }...),
         Math.avg(angles.map{ .deg2rad.cos }...),
-    ) -> rad2deg;
+    ) -> rad2deg
 }
 
 [[350,10], [90,180,270,360], [10,20,30]].each { |angles|
-  say "The mean angle of #{angles.dump} is: #{ '%.2f' % mean_angle(angles)} degrees";
+  say "The mean angle of #{angles.dump} is: #{ '%.2f' % mean_angle(angles)} degrees"
 }

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

@@ -0,0 +1,14 @@
+mata
+function meanangle(a) {
+return(arg(sum(exp(C(0,a)))))
+}
+
+deg=acos(-1)/180
+
+meanangle((350,10)*deg)/deg
+  -1.61481e-15
+meanangle((90,180,270,360)*deg)/deg
+  0
+meanangle((10,20,30)*deg)/deg
+  20
+end

Task/Averages-Mean-angle/Zkl/averages-mean-angle.zkl

@@ -0,0 +1,7 @@
+fcn meanA(a1,a2,etc){
+   as:=vm.arglist.pump(List,"toFloat","toRad");
+   n:=as.len();
+   (as.apply("sin").sum(0.0)/n)
+   .atan2(as.apply("cos").sum(0.0)/n)
+   .toDeg()
+}