ShortestPathTree.java
package org.drip.spaces.graph;
/*
* -*- mode: java; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
*/
/*!
* Copyright (C) 2020 Lakshmi Krishnamurthy
* Copyright (C) 2019 Lakshmi Krishnamurthy
* Copyright (C) 2018 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>ShortestPathTree</i> holds the Map of Vertex Peripheries by Weight and Vertex Name. The References are:
*
* <br><br>
* <ul>
* <li>
* Wikipedia (2018a): Graph (Abstract Data Type)
* https://en.wikipedia.org/wiki/Graph_(abstract_data_type)
* </li>
* <li>
* Wikipedia (2018b): Graph Theory https://en.wikipedia.org/wiki/Graph_theory
* </li>
* <li>
* Wikipedia (2018c): Graph (Discrete Mathematics)
* https://en.wikipedia.org/wiki/Graph_(discrete_mathematics)
* </li>
* <li>
* Wikipedia (2018d): Dijkstra's Algorithm https://en.wikipedia.org/wiki/Dijkstra%27s_algorithm
* </li>
* <li>
* Wikipedia (2018e): Bellman-Ford Algorithm
* https://en.wikipedia.org/wiki/Bellman%E2%80%93Ford_algorithm
* </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/StatisticalLearningLibrary.md">Statistical Learning Library</a></li>
* <li><b>Project</b> = <a href = "https://github.com/lakshmiDRIP/DROP/tree/master/src/main/java/org/drip/spaces/README.md">R<sup>1</sup> and R<sup>d</sup> Vector/Tensor Spaces (Validated and/or Normed), and Function Classes</a></li>
* <li><b>Package</b> = <a href = "https://github.com/lakshmiDRIP/DROP/tree/master/src/main/java/org/drip/spaces/graph/README.md">Graph Representation and Traversal Algorithms</a></li>
* </ul>
* <br><br>
*
* @author Lakshmi Krishnamurthy
*/
public class ShortestPathTree
{
private java.util.Map<java.lang.String, org.drip.spaces.graph.ShortestPathVertex> _nameIndex = new
org.drip.analytics.support.CaseInsensitiveHashMap<org.drip.spaces.graph.ShortestPathVertex>();
private java.util.Map<java.lang.Double, java.util.List<org.drip.spaces.graph.ShortestPathVertex>>
_weightIndex = new java.util.TreeMap<java.lang.Double,
java.util.List<org.drip.spaces.graph.ShortestPathVertex>>();
private org.drip.spaces.graph.ShortestPathVertex getUnvisited (
final java.util.List<org.drip.spaces.graph.ShortestPathVertex> shortestPathVertexList)
{
for (org.drip.spaces.graph.ShortestPathVertex shortestPathVertex : shortestPathVertexList)
{
if (!shortestPathVertex.visited())
{
return shortestPathVertex;
}
}
return null;
}
/**
* Empty ShortestPathTree Constructor
*/
public ShortestPathTree()
{
}
/**
* Add a shortestPathVertex
*
* @param shortestPathVertex The shortestPathVertex
*
* @return TRUE - The shortestPathVertex successfully added
*/
public boolean addShortestPathVertex (
final org.drip.spaces.graph.ShortestPathVertex shortestPathVertex)
{
if (null == shortestPathVertex)
{
return false;
}
_nameIndex.put (
shortestPathVertex.current(),
shortestPathVertex
);
double weightFromSource = shortestPathVertex.weightFromSource();
if (_weightIndex.containsKey (weightFromSource))
{
_weightIndex.get (shortestPathVertex.weightFromSource()).add (shortestPathVertex);
}
else
{
java.util.List<org.drip.spaces.graph.ShortestPathVertex> shortestPathVertexList = new
java.util.ArrayList<org.drip.spaces.graph.ShortestPathVertex>();
shortestPathVertexList.add (shortestPathVertex);
_weightIndex.put (
weightFromSource,
shortestPathVertexList
);
}
return true;
}
/**
* Add an Uninitialized ShortestPathVertex
*
* @param vertexName The Vertex Name
*
* @return TRUE - An Uninitialized ShortestPathVertex successfully added
*/
public boolean addUnitializedShortestPathVertex (
final java.lang.String vertexName)
{
try
{
return addShortestPathVertex (new org.drip.spaces.graph.ShortestPathVertex (vertexName));
}
catch (java.lang.Exception e)
{
e.printStackTrace();
}
return false;
}
/**
* Indicate of the Vertex is available in the Periphery Map
*
* @param vertexName The Vertex Name
*
* @return TRUE - The Vertex is available in the Periphery Map
*/
public boolean containsVertex (
final java.lang.String vertexName)
{
return null != vertexName && !vertexName.isEmpty() && _nameIndex.containsKey (vertexName);
}
/**
* Retrieve the Vertex Periphery by Name
*
* @param vertexName The Vertex Name
*
* @return The Vertex Periphery by Name
*/
public org.drip.spaces.graph.ShortestPathVertex shortestPathVertex (
final java.lang.String vertexName)
{
return _nameIndex.containsKey (vertexName) ? _nameIndex.get (vertexName) : null;
}
/**
* Retrieve the Vertex Periphery with the least Weight
*
* @return The Vertex Periphery with the least Weight
*/
public org.drip.spaces.graph.ShortestPathVertex greedyShortestPathVertex()
{
for (java.util.Map.Entry<java.lang.Double, java.util.List<org.drip.spaces.graph.ShortestPathVertex>>
weightIndexEntry : _weightIndex.entrySet())
{
org.drip.spaces.graph.ShortestPathVertex vertexPeriphery = getUnvisited
(weightIndexEntry.getValue());
if (null == vertexPeriphery)
{
continue;
}
vertexPeriphery.setVisited (true);
return vertexPeriphery;
}
return null;
}
/**
* Retrieve the Name Indexed Vertex Periphery Map
*
* @return The Name Indexed Vertex Periphery Map
*/
public java.util.Map<java.lang.String, org.drip.spaces.graph.ShortestPathVertex> nameIndex()
{
return _nameIndex;
}
/**
* Retrieve the Weight Indexed Vertex Periphery Map
*
* @return The Weight Indexed Vertex Periphery Map
*/
public java.util.Map<java.lang.Double, java.util.List<org.drip.spaces.graph.ShortestPathVertex>>
weightIndex()
{
return _weightIndex;
}
}