2016 Update

Task/Arithmetic-geometric-mean/JavaScript/arithmetic-geometric-mean-1.js

@@ -0,0 +1,10 @@
+function agm(a0, g0) {
+    var an = (a0 + g0) / 2,
+        gn = Math.sqrt(a0 * g0);
+    while (Math.abs(an - gn) > tolerance) {
+        an = (an + gn) / 2, gn = Math.sqrt(an * gn)
+    }
+    return an;
+}
+
+agm(1, 1 / Math.sqrt(2));

Task/Arithmetic-geometric-mean/JavaScript/arithmetic-geometric-mean-2.js

@@ -0,0 +1,43 @@
+(() => {
+    'use strict';
+
+    // ARITHMETIC-GEOMETRIC MEAN
+
+    // agm :: Num a => a -> a -> a
+    let agm = (a, g) => {
+            let abs = Math.abs,
+                sqrt = Math.sqrt;
+
+            return until(
+                    m => abs(m.an - m.gn) < tolerance,
+                    m => {
+                        return {
+                            an: (m.an + m.gn) / 2,
+                            gn: sqrt(m.an * m.gn)
+                        };
+                    }, {
+                        an: (a + g) / 2,
+                        gn: sqrt(a * g)
+                    }
+                )
+                .an;
+        },
+
+        // GENERIC
+
+        // until :: (a -> Bool) -> (a -> a) -> a -> a
+        until = (p, f, x) => {
+            let v = x;
+            while (!p(v)) v = f(v);
+            return v;
+        };
+
+
+    // TEST
+
+    let tolerance = 0.000001;
+
+
+    return agm(1, 1 / Math.sqrt(2));
+
+})();

Task/Arithmetic-geometric-mean/JavaScript/arithmetic-geometric-mean-3.js

@@ -0,0 +1 @@
+0.8472130848351929

Task/Arithmetic-geometric-mean/JavaScript/arithmetic-geometric-mean.js

@@ -1,9 +0,0 @@
-function agm(a0,g0){
-var an=(a0+g0)/2,gn=Math.sqrt(a0*g0);
-while(Math.abs(an-gn)>tolerance){
-an=(an+gn)/2,gn=Math.sqrt(an*gn)
-}
-return an;
-}
-
-agm(1,1/Math.sqrt(2));