BuiltInEntry.java

package org.drip.function.e2erf;

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

/*!
 * Copyright (C) 2020 Lakshmi Krishnamurthy
 * Copyright (C) 2019 Lakshmi Krishnamurthy
 * 
 *  This file is part of DROP, an open-source library targeting analytics/risk, transaction cost analytics,
 *      asset liability management analytics, capital, exposure, and margin analytics, valuation adjustment
 *      analytics, and portfolio construction analytics within and across fixed income, credit, commodity,
 *      equity, FX, and structured products. It also includes auxiliary libraries for algorithm support,
 *      numerical analysis, numerical optimization, spline builder, model validation, statistical learning,
 *      and computational support.
 *  
 *      https://lakshmidrip.github.io/DROP/
 *  
 *  DROP is composed of three modules:
 *  
 *  - DROP Product Core - https://lakshmidrip.github.io/DROP-Product-Core/
 *  - DROP Portfolio Core - https://lakshmidrip.github.io/DROP-Portfolio-Core/
 *  - DROP Computational Core - https://lakshmidrip.github.io/DROP-Computational-Core/
 * 
 *  DROP Product Core implements libraries for the following:
 *  - Fixed Income Analytics
 *  - Loan Analytics
 *  - Transaction Cost Analytics
 * 
 *  DROP Portfolio Core implements libraries for the following:
 *  - Asset Allocation Analytics
 *  - Asset Liability Management Analytics
 *  - Capital Estimation Analytics
 *  - Exposure Analytics
 *  - Margin Analytics
 *  - XVA Analytics
 * 
 *  DROP Computational Core implements libraries for the following:
 *  - Algorithm Support
 *  - Computation Support
 *  - Function Analysis
 *  - Model Validation
 *  - Numerical Analysis
 *  - Numerical Optimizer
 *  - Spline Builder
 *  - Statistical Learning
 * 
 *  Documentation for DROP is Spread Over:
 * 
 *  - Main                     => https://lakshmidrip.github.io/DROP/
 *  - Wiki                     => https://github.com/lakshmiDRIP/DROP/wiki
 *  - GitHub                   => https://github.com/lakshmiDRIP/DROP
 *  - Repo Layout Taxonomy     => https://github.com/lakshmiDRIP/DROP/blob/master/Taxonomy.md
 *  - Javadoc                  => https://lakshmidrip.github.io/DROP/Javadoc/index.html
 *  - Technical Specifications => https://github.com/lakshmiDRIP/DROP/tree/master/Docs/Internal
 *  - Release Versions         => https://lakshmidrip.github.io/DROP/version.html
 *  - Community Credits        => https://lakshmidrip.github.io/DROP/credits.html
 *  - Issues Catalog           => https://github.com/lakshmiDRIP/DROP/issues
 *  - JUnit                    => https://lakshmidrip.github.io/DROP/junit/index.html
 *  - Jacoco                   => https://lakshmidrip.github.io/DROP/jacoco/index.html
 * 
 *  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.
 */

/**
 * <i>BuiltInEntry</i> implements E<sub>2</sub> Entries of the Built-in Table of erf and erfc Values. The
 * References are:
 * 
 * <br><br>
 *  <ul>
 *      <li>
 *          Abramowitz, M., and I. A. Stegun (2007): <i>Handbook of Mathematics Functions</i> <b>Dover Book
 *              on Mathematics</b>
 *      </li>
 *      <li>
 *          Chang, S. H., P. C. Cosman, L. B. Milstein (2011): Chernoff-Type Bounds for Gaussian Error
 *              Function <i>IEEE Transactions on Communications</i> <b>59 (11)</b> 2939-2944
 *      </li>
 *      <li>
 *          Cody, W. J. (1991): Algorithm 715: SPECFUN – A Portable FORTRAN Package of Special Function
 *              Routines and Test Drivers <i>ACM Transactions on Mathematical Software</i> <b>19 (1)</b>
 *              22-32
 *      </li>
 *      <li>
 *          Schopf, H. M., and P. H. Supancic (2014): On Burmann’s Theorem and its Application to Problems of
 *              Linear and Non-linear Heat Transfer and Diffusion
 *              https://www.mathematica-journal.com/2014/11/on-burmanns-theorem-and-its-application-to-problems-of-linear-and-nonlinear-heat-transfer-and-diffusion/#more-39602/
 *      </li>
 *      <li>
 *          Wikipedia (2019): Error Function https://en.wikipedia.org/wiki/Error_function
 *      </li>
 *  </ul>
 *
 *  <br><br>
 *  <ul>
 *      <li><b>Module </b> = <a href = "https://github.com/lakshmiDRIP/DROP/tree/master/ComputationalCore.md">Computational Core Module</a></li>
 *      <li><b>Library</b> = <a href = "https://github.com/lakshmiDRIP/DROP/tree/master/NumericalAnalysisLibrary.md">Numerical Analysis Library</a></li>
 *      <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>
 *      <li><b>Package</b> = <a href = "https://github.com/lakshmiDRIP/DROP/tree/master/src/main/java/org/drip/function/e2erf/README.md">E<sub>2</sub> erf and erf<sup>-1</sup> Implementations</a></li>
 *  </ul>
 *
 * @author Lakshmi Krishnamurthy
 */

public class BuiltInEntry
{
    private double _erf = java.lang.Double.NaN;
    private double _erfc = java.lang.Double.NaN;

    /**
     * Generate a Table of Built-in E<sub>2</sub> erf/erfc Entries
     * 
     * @return The Table of Built-in E<sub>2</sub> erf/erfc Entries
     */

    public static final java.util.Map<java.lang.Double, BuiltInEntry> Table()
    {
        java.util.Map<java.lang.Double, BuiltInEntry> builtInEntryTable = new
            java.util.TreeMap<java.lang.Double, BuiltInEntry>();

        try
        {
            builtInEntryTable.put (
                0.00,
                new BuiltInEntry (
                    0.000000000,
                    1.000000000
                )
            );

            builtInEntryTable.put (
                0.02,
                new BuiltInEntry (
                    0.022564575,
                    0.977435425
                )
            );

            builtInEntryTable.put (
                0.04,
                new BuiltInEntry (
                    0.045111106,
                    0.954888894
                )
            );

            builtInEntryTable.put (
                0.06,
                new BuiltInEntry (
                    0.067621594,
                    0.932378406
                )
            );

            builtInEntryTable.put (
                0.08,
                new BuiltInEntry (
                    0.090078126,
                    0.909921874
                )
            );

            builtInEntryTable.put (
                0.10,
                new BuiltInEntry (
                    0.112462916,
                    0.887537084
                )
            );

            builtInEntryTable.put (
                0.20,
                new BuiltInEntry (
                    0.222792589,
                    0.777297411
                )
            );

            builtInEntryTable.put (
                0.30,
                new BuiltInEntry (
                    0.328626759,
                    0.671373241
                )
            );

            builtInEntryTable.put (
                0.40,
                new BuiltInEntry (
                    0.428392355,
                    0.571607645
                )
            );

            builtInEntryTable.put (
                0.50,
                new BuiltInEntry (
                    0.520499878,
                    0.479500122
                )
            );

            builtInEntryTable.put (
                0.60,
                new BuiltInEntry (
                    0.603856091,
                    0.396143909
                )
            );

            builtInEntryTable.put (
                0.70,
                new BuiltInEntry (
                    0.677801194,
                    0.322198806
                )
            );

            builtInEntryTable.put (
                0.80,
                new BuiltInEntry (
                    0.742100965,
                    0.257899035
                )
            );

            builtInEntryTable.put (
                0.90,
                new BuiltInEntry (
                    0.796908212,
                    0.203091788
                )
            );

            builtInEntryTable.put (
                1.00,
                new BuiltInEntry (
                    0.842700793,
                    0.157299207
                )
            );

            builtInEntryTable.put (
                1.10,
                new BuiltInEntry (
                    0.880205070,
                    0.119794930
                )
            );

            builtInEntryTable.put (
                1.20,
                new BuiltInEntry (
                    0.910313978,
                    0.089686022
                )
            );

            builtInEntryTable.put (
                1.30,
                new BuiltInEntry (
                    0.934007945,
                    0.065992055
                )
            );

            builtInEntryTable.put (
                1.40,
                new BuiltInEntry (
                    0.952285120,
                    0.047714880
                )
            );

            builtInEntryTable.put (
                1.50,
                new BuiltInEntry (
                    0.966105146,
                    0.033894854
                )
            );

            builtInEntryTable.put (
                1.60,
                new BuiltInEntry (
                    0.976348383,
                    0.023651617
                )
            );

            builtInEntryTable.put (
                1.70,
                new BuiltInEntry (
                    0.983790459,
                    0.016209541
                )
            );

            builtInEntryTable.put (
                1.80,
                new BuiltInEntry (
                    0.989090502,
                    0.010909498
                )
            );

            builtInEntryTable.put (
                1.90,
                new BuiltInEntry (
                    0.992790429,
                    0.007209571
                )
            );

            builtInEntryTable.put (
                2.00,
                new BuiltInEntry (
                    0.995322265,
                    0.004677735
                )
            );

            builtInEntryTable.put (
                2.10,
                new BuiltInEntry (
                    0.997020533,
                    0.002979467
                )
            );

            builtInEntryTable.put (
                2.20,
                new BuiltInEntry (
                    0.998137154,
                    0.001862846
                )
            );

            builtInEntryTable.put (
                2.30,
                new BuiltInEntry (
                    0.998856823,
                    0.001143177
                )
            );

            builtInEntryTable.put (
                2.40,
                new BuiltInEntry (
                    0.999311486,
                    0.000688514
                )
            );

            builtInEntryTable.put (
                2.50,
                new BuiltInEntry (
                    0.999593048,
                    0.000406952
                )
            );

            builtInEntryTable.put (
                3.00,
                new BuiltInEntry (
                    0.999977910,
                    0.000022090
                )
            );

            builtInEntryTable.put (
                3.50,
                new BuiltInEntry (
                    0.999999257,
                    0.000000743
                )
            );

            return builtInEntryTable;
        }
        catch (java.lang.Exception e)
        {
            e.printStackTrace();
        }

        return null;
    }

    /**
     * BuiltInEntry Constructor
     * 
     * @param erf E<sub>2</sub> erf Value
     * @param erfc E<sub>2</sub> erfc Value
     * 
     * @throws java.lang.Exception Thrown if the Inputs are Invalid
     */

    public BuiltInEntry (
        final double erf,
        final double erfc)
        throws java.lang.Exception
    {
        if (!org.drip.numerical.common.NumberUtil.IsValid (_erf = erf) ||
            !org.drip.numerical.common.NumberUtil.IsValid (_erfc = erfc))
        {
            throw new java.lang.Exception ("BuiltInE2Entry Constructor => Invalid Inputs");
        }
    }

    /**
     * Retrieve the E<sub>2</sub> erf
     * 
     * @return The E<sub>2</sub> erf
     */

    public double erf()
    {
        return _erf;
    }

    /**
     * Retrieve the E<sub>2</sub> erfc
     * 
     * @return The E<sub>2</sub> erfc
     */

    public double erfc()
    {
        return _erfc;
    }
}