first commit

strategies/indicators/DEMA.js

@@ -0,0 +1,19 @@
+// required indicators
+var EMA = require('./EMA.js');
+
+var Indicator = function(config) {
+  this.input = 'price';
+  this.result = false;
+  this.inner = new EMA(config.weight);
+  this.outer = new EMA(config.weight);
+}
+
+// add a price and calculate the EMAs and
+// the result
+Indicator.prototype.update = function(price) {
+  this.inner.update(price);
+  this.outer.update(this.inner.result);
+  this.result = 2 * this.inner.result - this.outer.result;
+}
+
+module.exports = Indicator;