theplu::yat::utility::kNNI Class Reference

kNNimpute More...

#include <yat/utility/kNNI.h>

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

List of all members.

Public Member Functions
	kNNI (const utility::Matrix &matrix, const utility::Matrix &weight, const unsigned int neighbours)
unsigned int	estimate (void)
	Function doing kNNI imputation.
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_

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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

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Constructor & Destructor Documentation

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

Constructor

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Member Function Documentation

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.

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

(

void

)

const [inherited]

Returns:

indices of rows in data matrix not imputed

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

(

const

size_t

)

const [protected, inherited]

where C is the number of columns

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

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

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Member Data Documentation

const utility::Matrix& theplu::yat::utility::NNI::data_ [protected, inherited]

original data matrix

utility::Matrix theplu::yat::utility::NNI::imputed_data_ [protected, inherited]

data after imputation

unsigned int theplu::yat::utility::NNI::neighbours_ [protected, inherited]

number of neighbor to use

std::vector<size_t> theplu::yat::utility::NNI::not_imputed_ [protected, inherited]

which rows are not imputed due to lack of data

const utility::Matrix& theplu::yat::utility::NNI::weight_ [protected, inherited]

weight matrix

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

• yat/utility/kNNI.h