VariateIterationSelectorParams.java

  1. package org.drip.function.r1tor1solver;

  2. /*
  3.  * -*- mode: java; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
  4.  */

  5. /*!
  6.  * Copyright (C) 2020 Lakshmi Krishnamurthy
  7.  * Copyright (C) 2019 Lakshmi Krishnamurthy
  8.  * Copyright (C) 2018 Lakshmi Krishnamurthy
  9.  * Copyright (C) 2017 Lakshmi Krishnamurthy
  10.  * Copyright (C) 2016 Lakshmi Krishnamurthy
  11.  * Copyright (C) 2015 Lakshmi Krishnamurthy
  12.  * Copyright (C) 2014 Lakshmi Krishnamurthy
  13.  * Copyright (C) 2013 Lakshmi Krishnamurthy
  14.  * Copyright (C) 2012 Lakshmi Krishnamurthy
  15.  *
  16.  *  This file is part of DROP, an open-source library targeting analytics/risk, transaction cost analytics,
  17.  *      asset liability management analytics, capital, exposure, and margin analytics, valuation adjustment
  18.  *      analytics, and portfolio construction analytics within and across fixed income, credit, commodity,
  19.  *      equity, FX, and structured products. It also includes auxiliary libraries for algorithm support,
  20.  *      numerical analysis, numerical optimization, spline builder, model validation, statistical learning,
  21.  *      and computational support.
  22.  *  
  23.  *      https://lakshmidrip.github.io/DROP/
  24.  *  
  25.  *  DROP is composed of three modules:
  26.  *  
  27.  *  - DROP Product Core - https://lakshmidrip.github.io/DROP-Product-Core/
  28.  *  - DROP Portfolio Core - https://lakshmidrip.github.io/DROP-Portfolio-Core/
  29.  *  - DROP Computational Core - https://lakshmidrip.github.io/DROP-Computational-Core/
  30.  *
  31.  *  DROP Product Core implements libraries for the following:
  32.  *  - Fixed Income Analytics
  33.  *  - Loan Analytics
  34.  *  - Transaction Cost Analytics
  35.  *
  36.  *  DROP Portfolio Core implements libraries for the following:
  37.  *  - Asset Allocation Analytics
  38.  *  - Asset Liability Management Analytics
  39.  *  - Capital Estimation Analytics
  40.  *  - Exposure Analytics
  41.  *  - Margin Analytics
  42.  *  - XVA Analytics
  43.  *
  44.  *  DROP Computational Core implements libraries for the following:
  45.  *  - Algorithm Support
  46.  *  - Computation Support
  47.  *  - Function Analysis
  48.  *  - Model Validation
  49.  *  - Numerical Analysis
  50.  *  - Numerical Optimizer
  51.  *  - Spline Builder
  52.  *  - Statistical Learning
  53.  *
  54.  *  Documentation for DROP is Spread Over:
  55.  *
  56.  *  - Main                     => https://lakshmidrip.github.io/DROP/
  57.  *  - Wiki                     => https://github.com/lakshmiDRIP/DROP/wiki
  58.  *  - GitHub                   => https://github.com/lakshmiDRIP/DROP
  59.  *  - Repo Layout Taxonomy     => https://github.com/lakshmiDRIP/DROP/blob/master/Taxonomy.md
  60.  *  - Javadoc                  => https://lakshmidrip.github.io/DROP/Javadoc/index.html
  61.  *  - Technical Specifications => https://github.com/lakshmiDRIP/DROP/tree/master/Docs/Internal
  62.  *  - Release Versions         => https://lakshmidrip.github.io/DROP/version.html
  63.  *  - Community Credits        => https://lakshmidrip.github.io/DROP/credits.html
  64.  *  - Issues Catalog           => https://github.com/lakshmiDRIP/DROP/issues
  65.  *  - JUnit                    => https://lakshmidrip.github.io/DROP/junit/index.html
  66.  *  - Jacoco                   => https://lakshmidrip.github.io/DROP/jacoco/index.html
  67.  *
  68.  *  Licensed under the Apache License, Version 2.0 (the "License");
  69.  *      you may not use this file except in compliance with the License.
  70.  *  
  71.  *  You may obtain a copy of the License at
  72.  *      http://www.apache.org/licenses/LICENSE-2.0
  73.  *  
  74.  *  Unless required by applicable law or agreed to in writing, software
  75.  *      distributed under the License is distributed on an "AS IS" BASIS,
  76.  *      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  77.  *  
  78.  *  See the License for the specific language governing permissions and
  79.  *      limitations under the License.
  80.  */

  81. /**
  82.  * <i>VariateIterationSelectorParams</i> implements the control parameters for the compound variate selector
  83.  * scheme used in Brent's method.
  84.  * <br><br>
  85.  * Brent's method uses the following fields in VariateIterationSelectorParams to generate the next variate:
  86.  * <br>
  87.  * <ul>
  88.  *  <li>
  89.  *      The Variate Primitive that is regarded as the "fast" method
  90.  *  </li>
  91.  *  <li>
  92.  *      The Variate Primitive that is regarded as the "robust" method
  93.  *  </li>
  94.  *  <li>
  95.  *      The relative variate shift that determines when the "robust" method is to be invoked over the "fast"
  96.  *  </li>
  97.  *  <li>
  98.  *      The lower bound on the variate shift between iterations that serves as the fall-back to the "robust"
  99.  *  </li>
  100.  * </ul>
  101.  *
  102.  *  <br><br>
  103.  *  <ul>
  104.  *      <li><b>Module </b> = <a href = "https://github.com/lakshmiDRIP/DROP/tree/master/ComputationalCore.md">Computational Core Module</a></li>
  105.  *      <li><b>Library</b> = <a href = "https://github.com/lakshmiDRIP/DROP/tree/master/NumericalAnalysisLibrary.md">Numerical Analysis Library</a></li>
  106.  *      <li><b>Project</b> = <a href = "https://github.com/lakshmiDRIP/DROP/tree/master/src/main/java/org/drip/function/README.md">R<sup>d</sup> To R<sup>d</sup> Function Analysis</a></li>
  107.  *      <li><b>Package</b> = <a href = "https://github.com/lakshmiDRIP/DROP/tree/master/src/main/java/org/drip/function/r1tor1solver/README.md">Built-in R<sup>1</sup> To R<sup>1</sup> Solvers</a></li>
  108.  *  </ul>
  109.  *
  110.  * @author Lakshmi Krishnamurthy
  111.  */

  112. public class VariateIterationSelectorParams {
  113.     private int _iFastIteratorPrimitive = -1;
  114.     private int _iRobustIteratorPrimitive = -1;
  115.     private double _dblRelativeVariateShift = java.lang.Double.NaN;
  116.     private double _dblVariateShiftLowerBound = java.lang.Double.NaN;

  117.     /**
  118.      * Default VariateIterationSelectorParams constructor
  119.      */

  120.     public VariateIterationSelectorParams()
  121.     {
  122.         _dblRelativeVariateShift = 0.5;
  123.         _dblVariateShiftLowerBound = 0.01;
  124.         _iRobustIteratorPrimitive = org.drip.function.r1tor1solver.VariateIteratorPrimitive.BISECTION;
  125.         _iFastIteratorPrimitive =
  126.             org.drip.function.r1tor1solver.VariateIteratorPrimitive.INVERSE_QUADRATIC_INTERPOLATION;
  127.     }

  128.     /**
  129.      * VariateIterationSelectorParams constructor
  130.      *
  131.      * @param dblRelativeVariateShift Relative Variate Shift
  132.      * @param dblVariateShiftLowerBound Variant Shift Lower Bound
  133.      * @param iFastIteratorPrimitive Fast Iterator Primitive
  134.      * @param iRobustIteratorPrimitive Robust Iterator Primitive
  135.      *
  136.      * @throws java.lang.Exception Thrown if inputs are invalid
  137.      */

  138.     public VariateIterationSelectorParams (
  139.         final double dblRelativeVariateShift,
  140.         final double dblVariateShiftLowerBound,
  141.         final int iFastIteratorPrimitive,
  142.         final int iRobustIteratorPrimitive)
  143.         throws java.lang.Exception
  144.     {
  145.         if (!org.drip.numerical.common.NumberUtil.IsValid (_dblRelativeVariateShift = dblRelativeVariateShift) ||
  146.             !org.drip.numerical.common.NumberUtil.IsValid (_dblVariateShiftLowerBound =
  147.                 dblVariateShiftLowerBound))
  148.             throw new java.lang.Exception ("VariateIterationSelectorParams constructor: Invalid inputs!");
  149.     }

  150.     /**
  151.      * Retrieve the relative variate Shift
  152.      *
  153.      * @return Relative variate Shift
  154.      */

  155.     public double getRelativeVariateShift()
  156.     {
  157.         return _dblRelativeVariateShift;
  158.     }

  159.     /**
  160.      * Retrieve the Variate Shift lower bound
  161.      *
  162.      * @return Variate Shift lower bound
  163.      */

  164.     public double getVariateShiftLowerBound()
  165.     {
  166.         return _dblVariateShiftLowerBound;
  167.     }

  168.     /**
  169.      * Retrieve the variate iterator primitive meant for speed
  170.      *
  171.      * @return variate iterator primitive meant for speed
  172.      */

  173.     public int getFastVariateIteratorPrimitive()
  174.     {
  175.         return _iFastIteratorPrimitive;
  176.     }

  177.     /**
  178.      * Retrieve the variate iterator primitive meant for robustness
  179.      *
  180.      * @return variate iterator primitive meant for robustness
  181.      */

  182.     public int getRobustVariateIteratorPrimitive()
  183.     {
  184.         return _iRobustIteratorPrimitive;
  185.     }
  186. }