source: trunk/src/CrossValidation.cc @ 115

// $Id: CrossValidation.cc 115 2004-07-19 14:38:43Z peter $

// System includes
#include <vector>

// Thep C++ Tools
#include "random_singleton.h"
#include "CrossValidation.h"

namespace theplu {
namespace cpptools {  

  CrossValidation::CrossValidation(const size_t nof_samples, const size_t k)
    :count_(0),index_(std::vector<size_t>()), k_(k)
 
  { 
    index_.resize(nof_samples);
    for (size_t i=0; i<nof_samples; i++)
      index_[i]=i;
    my_uniform_rng a;
    random_shuffle(index_.begin(), index_.end(), a);
  }

  std::vector<size_t> CrossValidation::next()
  {
    if (count_==k_){
      count_=0;
      my_uniform_rng a;
      random_shuffle(index_.begin(), index_.end(), a);
    }
    
    size_t begin = int(index_.size()*count_/k_);
    count_++;
    size_t end = int(index_.size()*count_/k_);
    std::vector<size_t> training_set;
    for (size_t i=0; i<index_.size(); i++)
      if (i<begin || i>=end)
        training_set.push_back(index_[i]);
    return training_set ;
    
  }
  
}} // of namespace cpptools and namespace theplu