SecondOrderModifiedBessel.java

  1. package org.drip.specialfunction.ode;

  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>SecondOrderModifiedBessel</i> exposes the Coefficient Terms in the Modified Bessel ODE. The References
  76.  * are:
  77.  *
  78.  * <br><br>
  79.  *  <ul>
  80.  *      <li>
  81.  *          Abramowitz, M., and I. A. Stegun (2007): <i>Handbook of Mathematics Functions</i> <b>Dover Book
  82.  *              on Mathematics</b>
  83.  *      </li>
  84.  *      <li>
  85.  *          Arfken, G. B., and H. J. Weber (2005): <i>Mathematical Methods for Physicists 6<sup>th</sup>
  86.  *              Edition</i> <b>Harcourt</b> San Diego
  87.  *      </li>
  88.  *      <li>
  89.  *          Temme N. M. (1996): <i>Special Functions: An Introduction to the Classical Functions of
  90.  *              Mathematical Physics 2<sup>nd</sup> Edition</i> <b>Wiley</b> New York
  91.  *      </li>
  92.  *      <li>
  93.  *          Watson, G. N. (1995): <i>A Treatise on the Theory of Bessel Functions</i> <b>Cambridge University
  94.  *              Press</b>
  95.  *      </li>
  96.  *      <li>
  97.  *          Wikipedia (2019): Bessel Function https://en.wikipedia.org/wiki/Bessel_function
  98.  *      </li>
  99.  *  </ul>
  100.  *
  101.  *  <br><br>
  102.  *  <ul>
  103.  *      <li><b>Module </b> = <a href = "https://github.com/lakshmiDRIP/DROP/tree/master/ComputationalCore.md">Computational Core Module</a></li>
  104.  *      <li><b>Library</b> = <a href = "https://github.com/lakshmiDRIP/DROP/tree/master/FunctionAnalysisLibrary.md">Function Analysis Library</a></li>
  105.  *      <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>
  106.  *      <li><b>Package</b> = <a href = "https://github.com/lakshmiDRIP/DROP/tree/master/src/main/java/org/drip/specialfunction/ode/README.md">Special Function Ordinary Differential Equations</a></li>
  107.  *  </ul>
  108.  *
  109.  * @author Lakshmi Krishnamurthy
  110.  */

  111. public class SecondOrderModifiedBessel extends org.drip.specialfunction.ode.SecondOrder
  112. {
  113.     private double _alpha = java.lang.Double.NaN;

  114.     /**
  115.      * Construct the Standard Second Order Modified Bessel ODE
  116.      *
  117.      * @param alpha Alpha
  118.      *
  119.      * @return The Standard Second Order Modified Bessel ODE
  120.      */

  121.     public static final SecondOrderModifiedBessel Standard (
  122.         final double alpha)
  123.     {
  124.         try
  125.         {
  126.             return new SecondOrderModifiedBessel (
  127.                 alpha,
  128.                 new org.drip.function.definition.R2ToR1()
  129.                 {
  130.                     @Override public double evaluate (
  131.                         final double z,
  132.                         final double w)
  133.                         throws java.lang.Exception
  134.                     {
  135.                         if (!org.drip.numerical.common.NumberUtil.IsValid (z))
  136.                         {
  137.                             throw new java.lang.Exception
  138.                                 ("SecondOrderModifiedBessel::SecondOrder::evaluate => Invalid Inputs");
  139.                         }

  140.                         return z * z;
  141.                     }
  142.                 },
  143.                 new org.drip.function.definition.R2ToR1()
  144.                 {
  145.                     @Override public double evaluate (
  146.                         final double z,
  147.                         final double w)
  148.                         throws java.lang.Exception
  149.                     {
  150.                         if (!org.drip.numerical.common.NumberUtil.IsValid (z))
  151.                         {
  152.                             throw new java.lang.Exception
  153.                                 ("SecondOrderModifiedBessel::SecondOrder::evaluate => Invalid Inputs");
  154.                         }

  155.                         return z;
  156.                     }
  157.                 },
  158.                 new org.drip.function.definition.R2ToR1()
  159.                 {
  160.                     @Override public double evaluate (
  161.                         final double z,
  162.                         final double w)
  163.                         throws java.lang.Exception
  164.                     {
  165.                         if (!org.drip.numerical.common.NumberUtil.IsValid (z) ||
  166.                             !org.drip.numerical.common.NumberUtil.IsValid (w))
  167.                         {
  168.                             throw new java.lang.Exception
  169.                                 ("SecondOrderModifiedBessel::SecondOrder::evaluate => Invalid Inputs");
  170.                         }

  171.                         return -1. * (z * z + alpha * alpha) * w;
  172.                     }
  173.                 }
  174.             );
  175.         }
  176.         catch (java.lang.Exception e)
  177.         {
  178.             e.printStackTrace();
  179.         }

  180.         return null;
  181.     }

  182.     private SecondOrderModifiedBessel (
  183.         final double alpha,
  184.         final org.drip.function.definition.R2ToR1 secondDerivativeCoefficient,
  185.         final org.drip.function.definition.R2ToR1 firstDerivativeCoefficient,
  186.         final org.drip.function.definition.R2ToR1 zeroDerivativeCoefficient)
  187.         throws java.lang.Exception
  188.     {
  189.         super (
  190.             secondDerivativeCoefficient,
  191.             firstDerivativeCoefficient,
  192.             zeroDerivativeCoefficient
  193.         );

  194.         if (!org.drip.numerical.common.NumberUtil.IsValid(_alpha = alpha))
  195.         {
  196.             throw new java.lang.Exception ("SecondOrderModifiedBessel Constructor => Invalid Inputs");
  197.         }
  198.     }

  199.     /**
  200.      * Retrieve the Alpha
  201.      *
  202.      * @return Alpha
  203.      */

  204.     public double alpha()
  205.     {
  206.         return _alpha;
  207.     }

  208.     @Override public java.util.TreeSet<java.lang.Double> orderedRegularSingularPoints()
  209.     {
  210.         return null;
  211.     }
  212. }