September 2017 Update

Task/Monte-Carlo-methods/JavaScript/monte-carlo-methods-2.js

@@ -0,0 +1,30 @@
+(() => {
+    'use strict';
+
+    // monteCarloPi :: Int -> Float
+    const monteCarloPi = n =>
+        4 * range(1, n)
+        .reduce(a => {
+            const [x, y] = [rnd(), rnd()];
+            return x * x + y * y < 1 ? a + 1 : a;
+        }, 0) / n;
+
+
+    // GENERIC FUNCTIONS
+
+    // range :: Int -> Int -> [Int]
+    const range = (m, n) =>
+        Array.from({
+            length: Math.floor(n - m) + 1
+        }, (_, i) => m + i);
+
+    // rnd :: () -> Float
+    const rnd = Math.random;
+
+
+    // TEST with from 1000 samples to 10E8 samples
+    return range(3, 8)
+        .map(x => monteCarloPi(Math.pow(10, x)));
+
+    // e.g. -> [3.14, 3.1404, 3.13304, 3.142408, 3.1420304, 3.14156788]
+})();