first commit

strategies/indicators/SMMA.js

@@ -0,0 +1,28 @@
+// required indicators
+var SMA = require('./SMA');
+
+var Indicator = function (weight) {
+  this.input = 'price';
+  this.sma = new SMA(weight);
+  this.weight = weight;
+  this.prices = [];
+  this.result = 0;
+  this.age = 0;
+}
+
+Indicator.prototype.update = function (price) {
+  this.prices[this.age] = price;
+
+  if(this.prices.length < this.weight) {
+    this.sma.update(price);
+  } else if(this.prices.length === this.weight) {
+    this.sma.update(price);
+    this.result = this.sma.result;
+  } else {
+    this.result = (this.result * (this.weight - 1) + price) / this.weight;
+  }
+
+  this.age++;
+}
+
+module.exports = Indicator;