.. _program_listing_file_lib_KDE.hpp:

Program Listing for File KDE.hpp
================================

|exhale_lsh| :ref:`Return to documentation for file <file_lib_KDE.hpp>` (``lib/KDE.hpp``)

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

.. code-block:: cpp

   #pragma once
   
   #include "rng.hpp"
   #include "utils.hpp"
   #include <boost/range/numeric.hpp>
   #include <random>
   
   template <class T>
   T select_random_element(std::vector<T> v,
                           std::mt19937& gen,
                           std::uniform_real_distribution<double>& uni_dist) {
     using namespace std;
     T element;
     if (v.size() == 0) {
       throw runtime_error(
           "Vector is empty, so we cannot select a random element from it. "
           "(function: select_random_element)\n");
     }
     else if (v.size() == 1) {
       element = v[0];
     }
     else {
       // Sample a double between [0, 1]
       double rand_val = uni_dist(gen);
   
       // Convert random double between [0, 1] into
       // an integer between [0, v.size() - 1
       unsigned long int idx = trunc(rand_val * v.size());
       if(idx == v.size()) {
         idx--;
       }
   
       element = v[idx];
     }
     return element;
   }
   
   double sample_from_normal(double mu, double sd);
   
   class KDE {
     public:
     KDE(){};
     std::vector<double> dataset = {};
     std::vector<double> log_prior_hist = {};
     double delta_theta = 1;
     int n_bins = 1;
     double bw; // bandwidth
     KDE(std::vector<double>);
     KDE(std::vector<double>, int n_bins);
     void set_num_bins(int n_bins);
     int theta_to_bin(double theta);
   
     // TODO: Made this public just to initialize β.
     // Not sure this is the correct way to do it.
     double mu = 0;
     double most_probable_theta = 0;
   
     std::vector<double> resample(int n_samples,
                                  std::mt19937& rng,
                                  std::uniform_real_distribution<double>& uni_dist,
                                  std::normal_distribution<double>& norm_dist);
     std::vector<double> resample(int n_samples);
     double pdf(double x);
     std::vector<double> pdf(std::vector<double> v);
     double logpdf(double x);
   };