From dabfb64ac6f6d1bea502097e7d260ce068ce06da Mon Sep 17 00:00:00 2001
From: wassname <wassname@users.noreply.github.com>
Date: Sat, 1 Dec 2018 16:54:16 +0800
Subject: [PATCH] make class

---
 src/js/utils.js | 27 ++++++++++++++++++++++++++-
 1 file changed, 26 insertions(+), 1 deletion(-)

diff --git a/src/js/utils.js b/src/js/utils.js
index fbf2ccd..7a50b1b 100644
--- a/src/js/utils.js
+++ b/src/js/utils.js
@@ -4,4 +4,29 @@ function deg2rad(deg) {
   return deg / 180 * Math.PI
 }
 
-module.exports = {deg2rad, randf}
+
+class MovingAverage{
+  constructor(N) {
+    this.N = N
+    this.buffer = []
+  }
+  add(val) {
+    if (this.buffer.length > this.N) this.buffer.splice(0, 1)
+    this.buffer.push(val)
+  }
+  mean() { 
+    return mean(this.buffer)
+  }
+}
+
+
+function mean(array){
+  if (array.length == 0)
+      return null;
+  var sum = array.reduce(function(a, b) { return a + b; });
+  var avg = sum / array.length;
+  return avg;
+}
+
+
+module.exports = {deg2rad, randf, MovingAverage, mean}