https://najibprog.github.io/najiberrami/Recent content on Najib ERRAMIHugoen-usThu, 06 Apr 2023 15:00:53 +0100https://najibprog.github.io/najiberrami/contributions/vrpsolvereasy/Thu, 06 Apr 2023 15:00:53 +0100https://najibprog.github.io/najiberrami/contributions/vrpsolvereasy/<h1 id="heading"></h1> <h2 id="project-overview">Project Overview</h2> <p>VRPSolverEasy is an advanced optimization library designed to solve Vehicle Routing Problems (VRP) and its variants using sophisticated Branch and Price algorithms. The project provides a comprehensive solution for researchers and practitioners in logistics, transportation, and optimization.</p> <h2 id="repository">Repository</h2> <p>🔗 <strong>GitHub</strong>: <a href="https://github.com/inria-UFF/VRPSolverEasy/">https://github.com/inria-UFF/VRPSolverEasy/</a></p> <h2 id="article">Article</h2> <p>📄 <strong>Publication</strong>: <a href="https://pubsonline.informs.org/doi/abs/10.1287/ijoc.2023.0103">VRPSolverEasy: A Python Library for the Exact Solution of a Rich Vehicle Routing Problem</a></p> <h2 id="technical-architecture">Technical Architecture</h2> <h3 id="core-technologies">Core Technologies</h3> <ul> <li><strong>Languages</strong>: C++, Python</li> <li><strong>Field</strong>: Integer Linear Programming</li> <li><strong>Optimization Techniques</strong>: Branch and Cut and Price Algorithm</li> </ul> <h3 id="key-components">Key Components</h3> <ol> <li> <p><strong>C++ Optimization Core</strong></p>https://najibprog.github.io/najiberrami/contributions/xloptim/Tue, 01 Dec 2020 15:00:53 +0100https://najibprog.github.io/najiberrami/contributions/xloptim/<h2 id="technical-overview">Technical Overview</h2> <p>XLOptim was a specialized optimization add-on for Excel, developed by XLSTAT (later acquired by Lumivero) as a proof of concept that leveraged LocalSolver(Hexaly)&rsquo;s powerful local search optimization engine.</p> <h2 id="core-technology-c-to-vba-wrapper">Core Technology: C++ to VBA Wrapper</h2> <h3 id="technical-architecture">Technical Architecture</h3> <h4 id="wrapper-technology">Wrapper Technology</h4> <ul> <li><strong>Language Bridge</strong>: Custom C++ to VBA wrapper</li> <li><strong>Purpose</strong>: Enable seamless integration of LocalSolver&rsquo;s C++ optimization engine with Excel&rsquo;s VBA environment</li> <li><strong>Key Components</strong>: <ul> <li>C++ Dynamic Link Library (DLL)</li> <li>VBA Interface Module</li> <li>Memory Management Layer</li> <li>Optimization Algorithm Translations</li> </ul> </li> </ul> <h4 id="wrapper-functionality">Wrapper Functionality</h4> <ul> <li><strong>Data Translation</strong>: Convert Excel cell ranges to C++ data structures</li> <li><strong>Optimization Engine Calls</strong>: Translate VBA parameters to mathematical model</li> <li><strong>Result Propagation</strong>: Return optimization results back to Excel spreadsheets</li> <li><strong>Error Handling</strong>: Robust error management between C++ and VBA contexts</li> </ul> <h2 id="optimization-approach">Optimization Approach</h2> <h3 id="localsolver-integration">LocalSolver Integration</h3> <ul> <li><strong>Search Strategy</strong>: Local search metaheuristics</li> <li><strong>Optimization Types</strong>: <ul> <li>Continuous optimization</li> <li>Discrete optimization</li> <li>Mixed-integer optimization</li> </ul> </li> </ul> <h3 id="excel-add-on-capabilities">Excel Add-On Capabilities</h3> <ul> <li>Direct optimization within Excel spreadsheets</li> <li>Support for complex constraint modeling</li> <li>Rapid solving of optimization problems</li> <li>Seamless integration with existing Excel workflows</li> </ul> <h2 id="development-context">Development Context</h2> <ul> <li><strong>Creator</strong>: XLSTAT Research Team</li> <li><strong>Technological Foundation</strong>: LocalSolver&rsquo;s optimization engine</li> <li><strong>Acquisition</strong>: Integrated into Lumivero&rsquo;s product portfolio</li> </ul> <h2 id="technical-challenges-solved">Technical Challenges Solved</h2> <ol> <li>Bridging C++ high-performance computing with Excel&rsquo;s VBA</li> <li>Translating complex mathematical models across language boundaries</li> <li>Maintaining performance while providing user-friendly interface</li> <li>Robust error handling in mixed-language environment</li> </ol> <h2 id="wrapper-technical-challenges">Wrapper Technical Challenges</h2> <ul> <li><strong>Memory Management</strong>: Preventing memory leaks</li> <li><strong>Data Type Conversion</strong>: Handling numerical precision</li> <li><strong>Performance Optimization</strong>: Minimizing overhead</li> <li><strong>Error Propagation</strong>: Consistent error reporting</li> </ul> <h2 id="use-cases">Use Cases</h2> <ul> <li>Financial modeling</li> <li>Resource allocation</li> <li>Production planning</li> <li>Portfolio optimization</li> <li>Scheduling problems</li> </ul>