#include <yat/utility/kNNI.h>

Inheritance diagram for theplu::yat::utility::kNNI:

Public Member Functions
	kNNI (const utility::Matrix &matrix, const utility::Matrix &weight, const unsigned int neighbours)

unsigned int	estimate (void)
	Function doing kNNI imputation. More...

const utility::Matrix &	imputed_data (void) const

const std::vector< size_t > &	not_imputed (void) const

Protected Member Functions
std::vector< std::pair< size_t, double > >	calculate_distances (const size_t) const

std::vector< size_t >	nearest_neighbours (const size_t, const std::vector< std::pair< size_t, double > > &) const

Protected Attributes
const utility::Matrix &	data_

utility::Matrix	imputed_data_

unsigned int	neighbours_

std::vector< size_t >	not_imputed_

const utility::Matrix &	weight_

Detailed Description

kNNimpute

kNNI is the binary weight implementation of NNI. This follows the work done by Troyanskaya et al. cited in the NNI document referred to in the NNI class documentation.

This is a special case of the WeNNI, but is maintained since it is faster than the more general WeNNI.

See Also: NNI and WeNNI

Constructor & Destructor Documentation

theplu::yat::utility::kNNI::kNNI	(	const utility::Matrix &	matrix,
		const utility::Matrix &	weight,
		const unsigned int	neighbours
	)

Constructor

Member Function Documentation

std::vector<std::pair<size_t,double> > theplu::yat::utility::NNI::calculate_distances ( const size_t ) const

protectedinherited

$d_{ij}^2=\frac {\sum_{k=1}^C w_{ik} w_{jk} (x_{ik}-x_{jk})^2 }{\sum_{k=l}^C w_{ik} w_{jk} }$ where C is the number of columns

unsigned int theplu::yat::utility::kNNI::estimate ( void )

virtual

Function doing kNNI imputation.

Perform kNNI on data in matrix with binary uncertainty weights in weight using neighbours for the new impute value.

The return value can be used as an indication of how well the imputation worked. The return value should be zero if proper pre-processing of data is done. An example of bad data is a matrix with a column of zero weights, another is a corresponding situation with a row with all weights zero.

Returns: The number of rows that have at least one value not imputed.

Implements theplu::yat::utility::NNI.

const utility::Matrix& theplu::yat::utility::NNI::imputed_data ( void ) const

inherited

Returns: A const reference to the modified data.

std::vector<size_t> theplu::yat::utility::NNI::nearest_neighbours	(	const size_t	,
		const std::vector< std::pair< size_t, double > > &
	)		const

protectedinherited

Contributing nearest neighbours are added up to the user set number, and neighbours are disqualified if their element (column) weight is zero

const std::vector<size_t>& theplu::yat::utility::NNI::not_imputed ( void ) const

inherited

Returns: indices of rows in data matrix not imputed

Member Data Documentation

const utility::Matrix& theplu::yat::utility::NNI::data_

protectedinherited

original data matrix

utility::Matrix theplu::yat::utility::NNI::imputed_data_

protectedinherited

data after imputation

unsigned int theplu::yat::utility::NNI::neighbours_

protectedinherited

number of neighbor to use

std::vector<size_t> theplu::yat::utility::NNI::not_imputed_

protectedinherited

which rows are not imputed due to lack of data

const utility::Matrix& theplu::yat::utility::NNI::weight_

protectedinherited

weight matrix

The documentation for this class was generated from the following file:

yat/utility/kNNI.h

Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation