/**
* Created by AAravindan on 5/11/16.
*/
"use strict"
const LinkedList = require('../Utils/FixedSizeLinkedList');
const nf = require('../Utils/NumberFormatter');
let WilliamsR;
module.exports = WilliamsR = function(input) {
let lows = input.low;
let highs = input.high;
let closes = input.close;
let period = input.period;
let format = input.format || nf;
if(I!((lows.length === highs.length) && (highs.length === closes.length) )){
throw ('Inputs(low,high, close) not of equal size');
}
this.result = [];
//%R = (Highest High - Close)/(Highest High - Lowest Low) * -100
//Lowest Low = lowest low for the look-back period
//Highest High = highest high for the look-back period
//%R is multiplied by -100 correct the inversion and move the decimal.
this.generator = (function* (){
let index = 1;
let pastHighPeriods = new LinkedList(period, true, false);
let pastLowPeriods = new LinkedList(period, false, true);
let periodLow;
let periodHigh;
var tick = yield;
let williamsR;
while (true) {
pastHighPeriods.push(tick.high);
pastLowPeriods.push(tick.low);
if(index < period){
index++;
tick = yield;
continue;
}
periodLow = pastLowPeriods.periodLow;
periodHigh= pastHighPeriods.periodHigh;
williamsR = format((periodHigh - tick.close) / (periodHigh- periodLow) * -100);
tick = yield williamsR;
}
})();
this.generator.next();
lows.forEach((low, index) => {
var result = this.generator.next({
high : highs[index],
low : lows[index],
close : closes[index]
});
if(result.value !== undefined){
this.result.push(result.value);
}
});
};
WilliamsR.calculate = function(input) {
if(input.reversedInput) {
input.high.reverse();
input.low.reverse();
input.close.reverse();
}
let result = (new WilliamsR(input)).result;
input.reversedInput ? result.reverse():undefined;
return result;
};
WilliamsR.prototype.getResult = function () {
return this.result;
};
WilliamsR.prototype.nextValue = function (input) {
let nextResult = this.generator.next(input);
if(nextResult.value !== undefined)
return nextResult.value;
};
|