.. _program_listing_file_environment_plasma_tec_neldermead.h:

Program Listing for File neldermead.h
=====================================

|exhale_lsh| :ref:`Return to documentation for file <file_environment_plasma_tec_neldermead.h>` (``environment/plasma/tec/neldermead.h``)

.. |exhale_lsh| unicode:: U+021B0 .. UPWARDS ARROW WITH TIP LEFTWARDS

.. code-block:: cpp

   
   
   #pragma once
   
   #include <algorithm>
   #include <array>
   #include <cmath>
   #include <functional>
   #include <iostream>
   
   #include "lupnt/environment/plasma/core/definitions.h"  // Vec2d definition
   
   namespace pecsim {
   
     struct SimplexVertex {
       Vec2d x;
       double fval;
     };
   
     class NelderMead {
     public:
       NelderMead(std::function<double(Vec2d)> func);
       NelderMead(std::function<double(Vec2d)> func, Vec2d x0, double step = 1.0, bool debug = false);
       Vec2d minimize(int max_iters = 200, double tol = 1e-6, double fval_tol = 0.0,
                      bool debug = false);
   
       void set_initial_simplex(Vec2d x0, double step = 1.0, bool debug = false);
       void set_initial_simplex(Vec2d x0, double f0, double step = 1.0, bool debug = false);
       int get_iter() const { return iter_; }
       double get_min_val() const { return min_val_; }
   
     private:
       int iter_ = 0;          // Current iteration number
       double min_val_ = 0.0;  // Minimum function value found
       std::function<double(Vec2d)> f;
       std::array<SimplexVertex, 3> simplex;
       Vec2d mean_point(const std::array<Vec2d, 2>& points);
       Vec2d reflect(const Vec2d& c, const Vec2d& worst, double alpha = 1.0);
       Vec2d expand(const Vec2d& c, const Vec2d& reflected, double gamma = 2.0);
       Vec2d contract(const Vec2d& c, const Vec2d& worst, double rho = 0.5);
       void shrink(double sigma = 0.5);
     };
   
   };  // namespace pecsim