/**
* The MIT License (MIT)
*
* Copyright (c) 2014-2017 Marc de Verdelhan & respective authors (see AUTHORS)
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of
* this software and associated documentation files (the "Software"), to deal in
* the Software without restriction, including without limitation the rights to
* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
* the Software, and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
package eu.verdelhan.ta4j.indicators.oscillators;
import eu.verdelhan.ta4j.Decimal;
import eu.verdelhan.ta4j.Indicator;
import eu.verdelhan.ta4j.TimeSeries;
import eu.verdelhan.ta4j.indicators.CachedIndicator;
import eu.verdelhan.ta4j.indicators.simple.ClosePriceIndicator;
import eu.verdelhan.ta4j.indicators.trackers.SMAIndicator;
/**
* The Detrended Price Oscillator (DPO) indicator.
* <p>
* The Detrended Price Oscillator (DPO) is an indicator designed to remove trend
* from price and make it easier to identify cycles. DPO does not extend to the
* last date because it is based on a displaced moving average. However,
* alignment with the most recent is not an issue because DPO is not a momentum
* oscillator. Instead, DPO is used to identify cycles highs/lows and estimate
* cycle length.
* </p>
* @see http://stockcharts.com/school/doku.php?id=chart_school:technical_indicators:detrended_price_osci
*/
public class DPOIndicator extends CachedIndicator<Decimal> {
private final int timeFrame;
private final int timeShift;
private final Indicator<Decimal> price;
private final SMAIndicator sma;
/**
* Constructor.
* @param series the series
* @param timeFrame the time frame
*/
public DPOIndicator(TimeSeries series, int timeFrame) {
this(new ClosePriceIndicator(series), timeFrame);
}
/**
* Constructor.
* @param price the price
* @param timeFrame the time frame
*/
public DPOIndicator(Indicator<Decimal> price, int timeFrame) {
super(price);
this.timeFrame = timeFrame;
timeShift = timeFrame / 2 + 1;
this.price = price;
sma = new SMAIndicator(price, this.timeFrame);
}
@Override
protected Decimal calculate(int index) {
return price.getValue(index).minus(sma.getValue(index + timeShift));
}
}