InfiniteSumSeries.java

  1. package org.drip.specialfunction.loggamma;

  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>InfiniteSumSeries</i> implements Infinite Sum Series for Log Gamma Estimation. The References are:
  76.  *
  77.  * <br><br>
  78.  *  <ul>
  79.  *      <li>
  80.  *          Blagouchine, I. V. (2014): Re-discovery of Malmsten's Integrals, their Evaluation by Contour
  81.  *              Integration Methods, and some Related Results <i>Ramanujan Journal</i> <b>35 (1)</b> 21-110
  82.  *      </li>
  83.  *      <li>
  84.  *          Borwein, J. M., and R. M. Corless (2017): Gamma Function and the Factorial in the Monthly
  85.  *              https://arxiv.org/abs/1703.05349 <b>arXiv</b>
  86.  *      </li>
  87.  *      <li>
  88.  *          Davis, P. J. (1959): Leonhard Euler's Integral: A Historical Profile of the Gamma Function
  89.  *              <i>American Mathematical Monthly</i> <b>66 (10)</b> 849-869
  90.  *      </li>
  91.  *      <li>
  92.  *          Whitaker, E. T., and G. N. Watson (1996): <i>A Course on Modern Analysis</i> <b>Cambridge
  93.  *              University Press</b> New York
  94.  *      </li>
  95.  *      <li>
  96.  *          Wikipedia (2019): Gamma Function https://en.wikipedia.org/wiki/Gamma_function
  97.  *      </li>
  98.  *  </ul>
  99.  *
  100.  *  <br><br>
  101.  *  <ul>
  102.  *      <li><b>Module </b> = <a href = "https://github.com/lakshmiDRIP/DROP/tree/master/ComputationalCore.md">Computational Core Module</a></li>
  103.  *      <li><b>Library</b> = <a href = "https://github.com/lakshmiDRIP/DROP/tree/master/FunctionAnalysisLibrary.md">Function Analysis Library</a></li>
  104.  *      <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>
  105.  *      <li><b>Package</b> = <a href = "https://github.com/lakshmiDRIP/DROP/tree/master/src/main/java/org/drip/specialfunction/loggamma/README.md">Analytic/Series/Integral Log Gamma Estimators</a></li>
  106.  *  </ul>
  107.  *
  108.  * @author Lakshmi Krishnamurthy
  109.  */

  110. public class InfiniteSumSeries
  111. {

  112.     /**
  113.      * Construct the R<sup>1</sup> To R<sup>1</sup> Infinite Euler Sum Series
  114.      *
  115.      * @param termCount Count of the Number of Terms
  116.      *
  117.      * @return The R<sup>1</sup> To R<sup>1</sup> Infinite Euler Sum Series
  118.      */

  119.     public static final org.drip.numerical.estimation.R1ToR1Series Euler (
  120.         final int termCount)
  121.     {
  122.         try
  123.         {
  124.             java.util.TreeMap<java.lang.Integer, java.lang.Double> termWeightMap = new
  125.                 java.util.TreeMap<java.lang.Integer, java.lang.Double>();

  126.             for (int termIndex = 1; termIndex <= termCount; ++termIndex)
  127.             {
  128.                 termWeightMap.put (
  129.                     termIndex,
  130.                     1.
  131.                 );
  132.             }

  133.             return new org.drip.numerical.estimation.R1ToR1Series (
  134.                 org.drip.specialfunction.loggamma.InfiniteSumSeriesTerm.Euler(),
  135.                 false,
  136.                 termWeightMap
  137.             );
  138.         }
  139.         catch (java.lang.Exception e)
  140.         {
  141.             e.printStackTrace();
  142.         }

  143.         return null;
  144.     }

  145.     /**
  146.      * Construct the R<sup>1</sup> To R<sup>1</sup> Infinite Weierstrass Sum Series
  147.      *
  148.      * @param termCount Count of the Number of Terms
  149.      *
  150.      * @return The R<sup>1</sup> To R<sup>1</sup> Infinite Weierstrass Sum Series
  151.      */

  152.     public static final org.drip.numerical.estimation.R1ToR1Series Weierstrass (
  153.         final int termCount)
  154.     {
  155.         try
  156.         {
  157.             java.util.TreeMap<java.lang.Integer, java.lang.Double> termWeightMap = new
  158.                 java.util.TreeMap<java.lang.Integer, java.lang.Double>();

  159.             for (int termIndex = 1; termIndex <= termCount; ++termIndex)
  160.             {
  161.                 termWeightMap.put (
  162.                     termIndex,
  163.                     1.
  164.                 );
  165.             }

  166.             return new org.drip.numerical.estimation.R1ToR1Series (
  167.                 org.drip.specialfunction.loggamma.InfiniteSumSeriesTerm.Weierstrass(),
  168.                 false,
  169.                 termWeightMap
  170.             );
  171.         }
  172.         catch (java.lang.Exception e)
  173.         {
  174.             e.printStackTrace();
  175.         }

  176.         return null;
  177.     }

  178.     /**
  179.      * Construct the R<sup>1</sup> To R<sup>1</sup> Malmsten-Blagouchine Fourier Series
  180.      *
  181.      * @param termCount Count of the Number of Terms
  182.      *
  183.      * @return The R<sup>1</sup> To R<sup>1</sup> Malmsten-Blagouchine Fourier Series
  184.      */

  185.     public static final org.drip.numerical.estimation.R1ToR1Series Fourier (
  186.         final int termCount)
  187.     {
  188.         try
  189.         {
  190.             java.util.TreeMap<java.lang.Integer, java.lang.Double> termWeightMap = new
  191.                 java.util.TreeMap<java.lang.Integer, java.lang.Double>();

  192.             for (int termIndex = 1; termIndex <= termCount; ++termIndex)
  193.             {
  194.                 termWeightMap.put (
  195.                     termIndex,
  196.                     1.
  197.                 );
  198.             }

  199.             return new org.drip.numerical.estimation.R1ToR1Series (
  200.                 org.drip.specialfunction.loggamma.InfiniteSumSeriesTerm.Fourier(),
  201.                 false,
  202.                 termWeightMap
  203.             );
  204.         }
  205.         catch (java.lang.Exception e)
  206.         {
  207.             e.printStackTrace();
  208.         }

  209.         return null;
  210.     }

  211.     /**
  212.      * Construct the R<sup>1</sup> To R<sup>1</sup> Blagouchine (2015) Series
  213.      *
  214.      * @param termCount Count of the Number of Terms
  215.      *
  216.      * @return The R<sup>1</sup> To R<sup>1</sup> Blagouchine (2015) Series
  217.      */

  218.     public static final org.drip.numerical.estimation.R1ToR1Series Blagouchine2015 (
  219.         final int termCount)
  220.     {
  221.         try
  222.         {
  223.             java.util.TreeMap<java.lang.Integer, java.lang.Double> termWeightMap = new
  224.                 java.util.TreeMap<java.lang.Integer, java.lang.Double>();

  225.             for (int termIndex = 1; termIndex < termCount; ++termIndex)
  226.             {
  227.                 if (2 * termIndex != termCount)
  228.                 {
  229.                     termWeightMap.put (
  230.                         termIndex,
  231.                         1.
  232.                     );
  233.                 }
  234.             }

  235.             return new org.drip.numerical.estimation.R1ToR1Series (
  236.                 org.drip.specialfunction.loggamma.InfiniteSumSeriesTerm.Blagouchine2015(),
  237.                 false,
  238.                 termWeightMap
  239.             );
  240.         }
  241.         catch (java.lang.Exception e)
  242.         {
  243.             e.printStackTrace();
  244.         }

  245.         return null;
  246.     }
  247. }