randompartitioner.cpp

来自「dysii是一款非常出色的滤波函数库」· C++ 代码 · 共 46 行

#include "RandomPartitioner.hpp"

using namespace indii::ml::aux;

RandomPartitioner::~RandomPartitioner() {
  //
}

void RandomPartitioner::init(Partitioner::points& xws) {
  /* pre-condition */
  assert (xws.size() >= 2);

  Partitioner::points::iterator iter, end;
  double lower, upper, x;
  const unsigned int N = xws.front()->x.size();

  /* randomly select dimension */
  this->index = static_cast<unsigned int>(Random::uniform(0, N));

  /* split on midpoint of selected dimension */
  iter = xws.begin();
  end = xws.end();  
  lower = (*iter)->x(index);
  upper = lower;
  iter++;  
  while (iter != end) {
    x = (*iter)->x(index);
    if (x < lower) {
      lower = x;
    } else if (x > upper) {
      upper = x;
    }
    iter++;
  }
  this->value = (lower + upper) / 2.0;
}

Partitioner::Partition RandomPartitioner::assign(const aux::vector& x) {
  if (x(index) <= value) {
    return Partitioner::LEFT;
  } else {
    return Partitioner::RIGHT;
  }
}