"use strict"
const SMA = require('../moving_averages/SMA');
const SD = require('../Utils/SD');
const nf = require('../Utils/NumberFormatter');
let BollingerBands;
module.exports = BollingerBands = function(input) {
var period = input.period
var priceArray = input.values;
var stdDev = input.stdDev;
var format = input.format || nf;
var sma,sd;
this.result = [];
sma = new SMA({period : period, values :[], format : (v) => {return v}});
sd = new SD({period : period, values : [], format : (v) => {return v}});
this.generator = (function* (){
var result;
var tick;
var calcSMA;
var calcsd;
tick = yield;
while (true) {
calcSMA = sma.nextValue(tick);
calcsd = sd.nextValue(tick);
if(calcSMA){
let middle = format(calcSMA);
let upper = format(calcSMA + (calcsd * stdDev));
let lower = format(calcSMA - (calcsd * stdDev));
let pb = format((tick - lower) / (upper - lower));
result = {
middle : middle,
upper : upper,
lower : lower,
pb : pb
}
}
tick = yield result;
}
})();
this.generator.next();
priceArray.forEach((tick) => {
var result = this.generator.next(tick);
if(result.value){
this.result.push(result.value);
}
});
};
BollingerBands.calculate = function(input) {
input.reversedInput ? input.values.reverse(): undefined;
let result = (new BollingerBands(input)).result;
input.reversedInput ? result.reverse():undefined;
return result;
};
BollingerBands.prototype.getResult = function () {
return this.result;
};
BollingerBands.prototype.nextValue = function (price) {
return this.generator.next(price).value;
};
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