all tasks

Task/Standard-deviation/JavaScript/standard-deviation.js

@@ -0,0 +1,20 @@
+function running_stddev() {
+    var n = 0;
+    var sum = 0.0;
+    var sum_sq = 0.0;
+    return function(num) {
+        n++;
+        sum += num;
+        sum_sq += num*num;
+        return Math.sqrt( (sum_sq / n) - Math.pow(sum / n, 2) );
+    }
+}
+
+var sd = running_stddev();
+var nums = [2,4,4,4,5,5,7,9];
+var stddev = [];
+for (var i in nums)
+    stddev.push( sd(nums[i]) );
+
+// using WSH
+WScript.Echo(stddev.join(', ');