
package org.drip.sample.numerical;

import java.util.Map;

import org.drip.param.pricer.HestonOptionPricerParams;
import org.drip.pricer.option.HestonStochasticVolatilityAlgorithm;
import org.drip.quant.common.FormatUtil;
import org.drip.quant.fourier.PhaseAdjuster;

/*
 * -*- mode: java; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 */

/*!
 * Copyright (C) 2017 Lakshmi Krishnamurthy
 * Copyright (C) 2016 Lakshmi Krishnamurthy
 * Copyright (C) 2015 Lakshmi Krishnamurthy
 * Copyright (C) 2014 Lakshmi Krishnamurthy
 * 
 *  This file is part of DRIP, a free-software/open-source library for buy/side financial/trading model
 *  	libraries targeting analysts and developers
 *  	https://lakshmidrip.github.io/DRIP/
 *  
 *  DRIP is composed of four main libraries:
 *  
 *  - DRIP Fixed Income - https://lakshmidrip.github.io/DRIP-Fixed-Income/
 *  - DRIP Asset Allocation - https://lakshmidrip.github.io/DRIP-Asset-Allocation/
 *  - DRIP Numerical Optimizer - https://lakshmidrip.github.io/DRIP-Numerical-Optimizer/
 *  - DRIP Statistical Learning - https://lakshmidrip.github.io/DRIP-Statistical-Learning/
 * 
 *  - DRIP Fixed Income: Library for Instrument/Trading Conventions, Treasury Futures/Options,
 *  	Funding/Forward/Overnight Curves, Multi-Curve Construction/Valuation, Collateral Valuation and XVA
 *  	Metric Generation, Calibration and Hedge Attributions, Statistical Curve Construction, Bond RV
 *  	Metrics, Stochastic Evolution and Option Pricing, Interest Rate Dynamics and Option Pricing, LMM
 *  	Extensions/Calibrations/Greeks, Algorithmic Differentiation, and Asset Backed Models and Analytics.
 * 
 *  - DRIP Asset Allocation: Library for model libraries for MPT framework, Black Litterman Strategy
 *  	Incorporator, Holdings Constraint, and Transaction Costs.
 * 
 *  - DRIP Numerical Optimizer: Library for Numerical Optimization and Spline Functionality.
 * 
 *  - DRIP Statistical Learning: Library for Statistical Evaluation and Machine Learning.
 * 
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *   	you may not use this file except in compliance with the License.
 *   
 *  You may obtain a copy of the License at
 *  	http://www.apache.org/licenses/LICENSE-2.0
 *  
 *  Unless required by applicable law or agreed to in writing, software
 *  	distributed under the License is distributed on an "AS IS" BASIS,
 *  	WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  
 *  See the License for the specific language governing permissions and
 *  	limitations under the License.
 */

/**
 * PhaseTrackerComparison demonstrates the Log + Power Complex Number Phase Correction Functionality
 * 	implemented by three different ways for the calculation of the Inverse Fourier Transforms. The sample
 * 	problem chosen is the stochastic volatility evolution using the Heston Method.
 * 
 * @author Lakshmi Krishnamurthy
 */

public class PhaseTrackerComparison {

	private static final Map<Double, Double> PhaseSet (
		final double dblRho,
		final double dblKappa,
		final double dblSigma,
		final double dblTheta,
		final double dblLambda,
		final double dblStrike,
		final double dbTimeToExpiry,
		final double dblRiskFreeRate,
		final double dblSpot,
		final double dblSpotVolatility,
		final int iPhaseTrackerType)
		throws Exception
	{
		HestonOptionPricerParams fphp = new HestonOptionPricerParams (
			HestonStochasticVolatilityAlgorithm.PAYOFF_TRANSFORM_SCHEME_HESTON_1993,
			dblRho,
			dblKappa,
			dblSigma,
			dblTheta,
			dblLambda,
			iPhaseTrackerType
		);

		HestonStochasticVolatilityAlgorithm hsva = new HestonStochasticVolatilityAlgorithm (fphp);

		return hsva.recordPhase (
			dblStrike,
			dbTimeToExpiry,
			dblRiskFreeRate,
			dblSpot,
			dblSpotVolatility,
			true
		);
	}

	public static final void main (
		final String[] astrArgs)
		throws Exception
	{
		double dblRho = 0.3;
		double dblKappa = 1.;
		double dblSigma = 0.5;
		double dblTheta = 0.2;
		double dblLambda = 0.;

		double dblStrike = 1.;
		double dbTimeToExpiry = 0.5;
		double dblRiskFreeRate = 0.0;
		double dblSpot = 1.;
		double dblSpotVolatility = 0.1;

		Map<Double, Double> mapFreqPhaseNoAdjust = PhaseSet (
			dblRho,
			dblKappa,
			dblSigma,
			dblTheta,
			dblLambda,
			dblStrike,
			dbTimeToExpiry,
			dblRiskFreeRate,
			dblSpot,
			dblSpotVolatility,
			PhaseAdjuster.MULTI_VALUE_BRANCH_PHASE_TRACKER_NONE
		);

		Map<Double, Double> mapFreqPhaseRotationCount = PhaseSet (
			dblRho,
			dblKappa,
			dblSigma,
			dblTheta,
			dblLambda,
			dblStrike,
			dbTimeToExpiry,
			dblRiskFreeRate,
			dblSpot,
			dblSpotVolatility,
			PhaseAdjuster.MULTI_VALUE_BRANCH_PHASE_TRACKER_ROTATION_COUNT
		);

		Map<Double, Double> mapFreqPhaseKahlJackel = PhaseSet (
			dblRho,
			dblKappa,
			dblSigma,
			dblTheta,
			dblLambda,
			dblStrike,
			dbTimeToExpiry,
			dblRiskFreeRate,
			dblSpot,
			dblSpotVolatility,
			PhaseAdjuster.MULTI_VALUE_BRANCH_POWER_PHASE_TRACKER_KAHL_JACKEL
		);

		System.out.println ("\t|--------------------------------------------|");

		System.out.println ("\t|  u =>  NO CORECT | ROT COUNT | KAHL JACKEL |");

		System.out.println ("\t|--------------------------------------------|");

		for (Map.Entry<Double, Double> me : mapFreqPhaseKahlJackel.entrySet()) {
			Double dblKey = me.getKey();

			System.out.println ("\t|" +
				FormatUtil.FormatDouble (dblKey, 2, 0, 1.) + " =>  " +
				FormatUtil.FormatDouble (mapFreqPhaseNoAdjust.get (dblKey), 1, 6, 1.)  + " | " +
				FormatUtil.FormatDouble (mapFreqPhaseRotationCount.get (dblKey), 1, 6, 1.)  + " | " +
				FormatUtil.FormatDouble (mapFreqPhaseKahlJackel.get (dblKey), 1, 6, 1.) + "   |"
			);
		}

		System.out.println ("\t|--------------------------------------------|");
	}
}
