SchwarzTriangleMap.java

  1. package org.drip.specialfunction.group;

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

  74. /**
  75.  * <i>SchwarzTriangleMap</i> contains the Ratio of the Linearly Independent Solution pair corresponding to a
  76.  * given Singularity of the Hyper-geometric 2F1 Function. The References are:
  77.  *
  78.  * <br><br>
  79.  *  <ul>
  80.  *      <li>
  81.  *          Gessel, I., and D. Stanton (1982): Strange Evaluations of Hyper-geometric Series <i>SIAM Journal
  82.  *              on Mathematical Analysis</i> <b>13 (2)</b> 295-308
  83.  *      </li>
  84.  *      <li>
  85.  *          Koepf, W (1995): Algorithms for m-fold Hyper-geometric Summation <i>Journal of Symbolic
  86.  *              Computation</i> <b>20 (4)</b> 399-417
  87.  *      </li>
  88.  *      <li>
  89.  *          Lavoie, J. L., F. Grondin, and A. K. Rathie (1996): Generalization of Whipple’s Theorem on the
  90.  *              Sum of a (_2^3)F(a,b;c;z) <i>Journal of Computational and Applied Mathematics</i> <b>72</b>
  91.  *              293-300
  92.  *      </li>
  93.  *      <li>
  94.  *          National Institute of Standards and Technology (2019): Hyper-geometric Function
  95.  *              https://dlmf.nist.gov/15
  96.  *      </li>
  97.  *      <li>
  98.  *          Wikipedia (2019): Hyper-geometric Function https://en.wikipedia.org/wiki/Hypergeometric_function
  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/FunctionAnalysisLibrary.md">Function Analysis Library</a></li>
  106.  *      <li><b>Project</b> = <a href = "https://github.com/lakshmiDRIP/DROP/tree/master/src/main/java/org/drip/specialfunction/README.md">Special Function Implementation Analysis</a></li>
  107.  *      <li><b>Package</b> = <a href = "https://github.com/lakshmiDRIP/DROP/tree/master/src/main/java/org/drip/specialfunction/group/README.md">Special Function Singularity Solution Group</a></li>
  108.  *  </ul>
  109.  *
  110.  * @author Lakshmi Krishnamurthy
  111.  */

  112. public class SchwarzTriangleMap
  113. {
  114.     private double _singularity = java.lang.Double.NaN;
  115.     private double _connectionCoefficient = java.lang.Double.NaN;
  116.     private org.drip.function.definition.R1ToR1 _singularitySolution0 = null;
  117.     private org.drip.function.definition.R1ToR1 _singularitySolution1 = null;
  118.     private org.drip.function.definition.R1ToR1 _singularityAsymptoteOrderTerm = null;

  119.     /**
  120.      * SchwarzTriangleMap Constructor
  121.      *
  122.      * @param singularity The Singularity
  123.      * @param singularitySolution0 The Singularity Solution 0
  124.      * @param singularitySolution1 The Singularity Solution 1
  125.      * @param singularityAsymptoteOrderTerm The Singularity Asymptote Order Term
  126.      * @param connectionCoefficient The Connection Coefficient
  127.      *
  128.      * @throws java.lang.Exception Thrown if the Inputs are Invalid
  129.      */

  130.     public SchwarzTriangleMap (
  131.         final double singularity,
  132.         final org.drip.function.definition.R1ToR1 singularitySolution0,
  133.         final org.drip.function.definition.R1ToR1 singularitySolution1,
  134.         final org.drip.function.definition.R1ToR1 singularityAsymptoteOrderTerm,
  135.         final double connectionCoefficient)
  136.         throws java.lang.Exception
  137.     {
  138.         if (java.lang.Double.isNaN (_singularity = singularity) ||
  139.             null == (_singularitySolution0 = singularitySolution0) ||
  140.             null == (_singularitySolution1 = singularitySolution1) ||
  141.             null == (_singularityAsymptoteOrderTerm = singularityAsymptoteOrderTerm) ||
  142.             !org.drip.numerical.common.NumberUtil.IsValid (_connectionCoefficient = connectionCoefficient))
  143.         {
  144.             throw new java.lang.Exception ("SchwarzTriangleMap Constructor => Invalid Inputs");
  145.         }
  146.     }

  147.     /**
  148.      * Retrieve the Singularity
  149.      *
  150.      * @return The Singularity
  151.      */

  152.     public double singularity()
  153.     {
  154.         return _singularity;
  155.     }

  156.     /**
  157.      * Retrieve the Singularity Solution 0
  158.      *
  159.      * @return The Singularity Solution 0
  160.      */

  161.     public org.drip.function.definition.R1ToR1 singularitySolution0()
  162.     {
  163.         return _singularitySolution0;
  164.     }

  165.     /**
  166.      * Retrieve the Singularity Solution 1
  167.      *
  168.      * @return The Singularity Solution 1
  169.      */

  170.     public org.drip.function.definition.R1ToR1 singularitySolution1()
  171.     {
  172.         return _singularitySolution1;
  173.     }

  174.     /**
  175.      * Retrieve the Singularity Asymptote Order Term
  176.      *
  177.      * @return The Singularity Asymptote Order Term
  178.      */

  179.     public org.drip.function.definition.R1ToR1 singularityAsymptoteOrderTerm()
  180.     {
  181.         return _singularityAsymptoteOrderTerm;
  182.     }

  183.     /**
  184.      * Retrieve the Connection Coefficient
  185.      *
  186.      * @return The Connection Coefficient
  187.      */

  188.     public double connectionCoefficient()
  189.     {
  190.         return _connectionCoefficient;
  191.     }

  192.     /**
  193.      * Indicate if the Triangle Map is Conformal
  194.      *
  195.      * @return TRUE - The Triangle Map is Conformal
  196.      */

  197.     public boolean isConformal()
  198.     {
  199.         return 0. <= _connectionCoefficient && 1. > _connectionCoefficient;
  200.     }

  201.     /**
  202.      * Generate the s-Function corresponding to the Singularity Solution Pair
  203.      *
  204.      * @return The s-Function corresponding to the Singularity Solution Pair
  205.      */

  206.     public org.drip.function.definition.R1ToR1 sFunction()
  207.     {
  208.         return new org.drip.function.definition.R1ToR1 (null)
  209.         {
  210.             @Override public double evaluate (
  211.                 final double z)
  212.                 throws java.lang.Exception
  213.             {
  214.                 return _singularitySolution1.evaluate (z) / _singularitySolution0.evaluate (z);
  215.             }
  216.         };
  217.     }

  218.     /**
  219.      * Generate the Schwarz-Christoffel Triangle Vertex
  220.      *
  221.      * @return The Schwarz-Christoffel Triangle Vertex
  222.      */

  223.     public org.drip.specialfunction.group.SchwarzChristoffelVertex schwarzChristoffelVertex()
  224.     {
  225.         try
  226.         {
  227.             return new org.drip.specialfunction.group.SchwarzChristoffelVertex (
  228.                 new org.drip.function.definition.R1ToR1 (null)
  229.                 {
  230.                     @Override public double evaluate (
  231.                         final double z)
  232.                         throws java.lang.Exception
  233.                     {
  234.                         return java.lang.Math.pow (
  235.                             _singularityAsymptoteOrderTerm.evaluate (z),
  236.                             _connectionCoefficient
  237.                         );
  238.                     }
  239.                 },
  240.                 _singularityAsymptoteOrderTerm,
  241.                 java.lang.Math.PI * _connectionCoefficient
  242.             );
  243.         }
  244.         catch (java.lang.Exception e)
  245.         {
  246.             e.printStackTrace();
  247.         }

  248.         return null;
  249.     }
  250. }