SegmentBestFitResponse.java

  1. package org.drip.spline.params;

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

  80. /**
  81.  * <i>SegmentBestFitResponse </i>implements basis per-segment Fitness Penalty Parameter Set. Currently it
  82.  * contains the Best Fit Penalty Weight Grid Matrix and the corresponding Segment Local Predictor
  83.  * Ordinate/Response Match Pair.
  84.  *
  85.  * <br><br>
  86.  *  <ul>
  87.  *      <li><b>Module </b> = <a href = "https://github.com/lakshmiDRIP/DROP/tree/master/ComputationalCore.md">Computational Core Module</a></li>
  88.  *      <li><b>Library</b> = <a href = "https://github.com/lakshmiDRIP/DROP/tree/master/SplineBuilderLibrary.md">Spline Builder Library</a></li>
  89.  *      <li><b>Project</b> = <a href = "https://github.com/lakshmiDRIP/DROP/tree/master/src/main/java/org/drip/spline/README.md">Basis Splines and Linear Compounders across a Broad Family of Spline Basis Functions</a></li>
  90.  *      <li><b>Package</b> = <a href = "https://github.com/lakshmiDRIP/DROP/tree/master/src/main/java/org/drip/spline/params/README.md">Spline Segment Construction Control Parameters</a></li>
  91.  *  </ul>
  92.  * <br><br>
  93.  *
  94.  * @author Lakshmi Krishnamurthy
  95.  */

  96. public class SegmentBestFitResponse {
  97.     private double[] _adblWeight = null;
  98.     private double[] _adblResponse = null;
  99.     private double[] _adblPredictorOrdinate = null;

  100.     /**
  101.      * Construct the SegmentBestFitResponse Instance from the given Inputs
  102.      *
  103.      * @param adblPredictorOrdinate Array of Predictor Ordinates
  104.      * @param adblResponseValue Array of Response Values
  105.      * @param adblWeight Array of Weights
  106.      *
  107.      * @return Instance of SegmentBestFitResponse
  108.      */

  109.     public static final SegmentBestFitResponse Create (
  110.         final double[] adblPredictorOrdinate,
  111.         final double[] adblResponseValue,
  112.         final double[] adblWeight)
  113.     {
  114.         SegmentBestFitResponse frp = null;

  115.         try {
  116.             frp = new SegmentBestFitResponse (adblWeight, adblResponseValue, adblPredictorOrdinate);
  117.         } catch (java.lang.Exception e) {
  118.             e.printStackTrace();

  119.             return null;
  120.         }

  121.         return frp.normalizeWeights() ? frp : null;
  122.     }

  123.     /**
  124.      * Construct the SegmentBestFitResponse Instance from the given Predictor Ordinate/Response Pairs, using
  125.      *  Uniform Weightings.
  126.      *
  127.      * @param adblPredictorOrdinate Array of Predictor Ordinates
  128.      * @param adblResponseValue Array of Response Values
  129.      *
  130.      * @return Instance of SegmentBestFitResponse
  131.      */

  132.     public static final SegmentBestFitResponse Create (
  133.         final double[] adblPredictorOrdinate,
  134.         final double[] adblResponseValue)
  135.     {
  136.         if (!org.drip.numerical.common.NumberUtil.IsValid (adblPredictorOrdinate)) return null;

  137.         int iNumWeight = adblPredictorOrdinate.length;
  138.         double[] adblWeight = new double[iNumWeight];

  139.         for (int i = 0; i < iNumWeight; ++i)
  140.             adblWeight[i] = 1.;

  141.         return Create (adblPredictorOrdinate, adblResponseValue, adblWeight);
  142.     }

  143.     private SegmentBestFitResponse (
  144.         final double[] adblWeight,
  145.         final double[] adblResponse,
  146.         final double[] adblPredictorOrdinate)
  147.         throws java.lang.Exception
  148.     {
  149.         if (!org.drip.numerical.common.NumberUtil.IsValid (_adblWeight = adblWeight) ||
  150.             !org.drip.numerical.common.NumberUtil.IsValid (_adblResponse = adblResponse) ||
  151.                 !org.drip.numerical.common.NumberUtil.IsValid (_adblPredictorOrdinate = adblPredictorOrdinate))
  152.             throw new java.lang.Exception ("SegmentBestFitResponse ctr: Invalid Inputs");

  153.         int iNumPointsToFit = _adblWeight.length;

  154.         if (0 == iNumPointsToFit || _adblResponse.length != iNumPointsToFit ||
  155.             _adblPredictorOrdinate.length != iNumPointsToFit)
  156.             throw new java.lang.Exception ("SegmentBestFitResponse ctr: Invalid Inputs");
  157.     }

  158.     private boolean normalizeWeights()
  159.     {
  160.         double dblCumulativeWeight = 0.;
  161.         int iNumPointsToFit = _adblWeight.length;

  162.         for (int i = 0; i < iNumPointsToFit; ++i) {
  163.             if (_adblWeight[i] < 0.) return false;

  164.             dblCumulativeWeight += _adblWeight[i];
  165.         }

  166.         if (0. >= dblCumulativeWeight) return false;

  167.         for (int i = 0; i < iNumPointsToFit; ++i)
  168.             _adblWeight[i] /= dblCumulativeWeight;

  169.         return true;
  170.     }

  171.     /**
  172.      * Retrieve the Array of the Fitness Weights
  173.      *
  174.      * @return The Array of the Fitness Weights
  175.      */

  176.     public double[] weight()
  177.     {
  178.         return _adblWeight;
  179.     }

  180.     /**
  181.      * Retrieve the Indexed Fitness Weight Element
  182.      *
  183.      * @param iIndex The Element Index
  184.      *
  185.      * @return The Indexed Fitness Weight Element
  186.      *
  187.      * @throws java.lang.Exception Thrown if the Index is Invalid
  188.      */

  189.     public double weight (
  190.         final int iIndex)
  191.         throws java.lang.Exception
  192.     {
  193.         if (iIndex >= numPoint())
  194.             throw new java.lang.Exception ("SegmentBestFitResponse::weight => Invalid Index");

  195.         return _adblWeight[iIndex];
  196.     }

  197.     /**
  198.      * Retrieve the Array of Predictor Ordinates
  199.      *
  200.      * @return The Array of Predictor Ordinates
  201.      */

  202.     public double[] predictorOrdinate()
  203.     {
  204.         return _adblPredictorOrdinate;
  205.     }

  206.     /**
  207.      * Retrieve the Indexed Predictor Ordinate Element
  208.      *
  209.      * @param iIndex The Element Index
  210.      *
  211.      * @return The Indexed Predictor Ordinate Element
  212.      *
  213.      * @throws java.lang.Exception Thrown if the Index is Invalid
  214.      */

  215.     public double predictorOrdinate (
  216.         final int iIndex)
  217.         throws java.lang.Exception
  218.     {
  219.         if (iIndex >= numPoint())
  220.             throw new java.lang.Exception ("SegmentBestFitResponse::predictorOrdinate => Invalid Index");

  221.         return _adblPredictorOrdinate[iIndex];
  222.     }

  223.     /**
  224.      * Retrieve the Array of Responses
  225.      *
  226.      * @return The Array of Responses
  227.      */

  228.     public double[] response()
  229.     {
  230.         return _adblResponse;
  231.     }

  232.     /**
  233.      * Retrieve the Indexed Response Element
  234.      *
  235.      * @param iIndex The Element Index
  236.      *
  237.      * @return The Indexed Response Element
  238.      *
  239.      * @throws java.lang.Exception Thrown if the Index is Invalid
  240.      */

  241.     public double response (
  242.         final int iIndex)
  243.         throws java.lang.Exception
  244.     {
  245.         if (iIndex >= numPoint())
  246.             throw new java.lang.Exception ("SegmentBestFitResponse::response => Invalid Index");

  247.         return _adblResponse[iIndex];
  248.     }

  249.     /**
  250.      * Retrieve the Number of Fitness Points
  251.      *
  252.      * @return The Number of Fitness Points
  253.      */

  254.     public int numPoint()
  255.     {
  256.         return null == _adblResponse ? 0 : _adblResponse.length;
  257.     }
  258. }