// $Id: NNI.cc 1487 2008-09-10 08:41:36Z jari $
/*
Copyright (C) 2004 Jari Häkkinen
Copyright (C) 2005 Peter Johansson
Copyright (C) 2006 Jari Häkkinen
Copyright (C) 2007 Jari Häkkinen, Peter Johansson
Copyright (C) 2008 Peter Johansson
This file is part of the yat library, http://dev.thep.lu.se/yat
The yat library is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 3 of the
License, or (at your option) any later version.
The yat library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with yat. If not, see .
*/
#include "NNI.h"
#include "stl_utility.h"
#include
#include
#include
namespace theplu {
namespace yat {
namespace utility {
// For a discussion and motivation for various algorithm
// implementations here see the paper cited in the class definition
// documentation.
NNI::NNI(const utility::Matrix& matrix,const utility::Matrix& weight,
const unsigned int neighbours)
: data_(matrix), imputed_data_(matrix), neighbours_(neighbours),
weight_(weight)
{
}
// d_{ij}^2=\frac {\sum_{k=1,C} w_{ik} w_{jk} (x_{ik}-x_{jk})^2 }
// {\sum_{k=l,C} w_{ik} w_{jk} }
// where C is the number of columns
std::vector >
NNI::calculate_distances(const size_t row) const
{
std::vector > distance;
for (size_t i=0; i this_distance(i,0.0);
for (size_t j=0; j& NNI::not_imputed(void) const
{
return not_imputed_;
}
// Contributing nearest neighbours are added up to the user set
// number, and neighbours are disqualified if their element (column)
// weight is zero
std::vector
NNI::nearest_neighbours(const size_t column,
const std::vector >& d) const
{
std::vector index;
double contribs=0;
for (size_t i=0; ((i