theplu::yat::regression::OneDimensional Class Reference

Interface Class for One Dimensional fitting. More...

#include <yat/regression/OneDimensional.h>

Inheritance diagram for theplu::yat::regression::OneDimensional:

theplu::yat::regression::Linear theplu::yat::regression::Naive theplu::yat::regression::Polynomial

List of all members.

Public Member Functions

 OneDimensional (void)
 The default constructor.
virtual ~OneDimensional (void)
 The destructor.
double chisq (void) const
 Chi-squared.
virtual void fit (const utility::VectorBase &x, const utility::VectorBase &y)=0
virtual double predict (const double x) const =0
double prediction_error2 (const double x) const
std::ostream & print (std::ostream &os, const double min, double max, const unsigned int n) const
 print output to ostream os
double r2 (void) const
virtual double s2 (void) const =0
virtual double standard_error2 (const double x) const =0

Protected Member Functions

double variance (void) const

Protected Attributes

statistics::AveragerPair ap_
double chisq_


Detailed Description

Interface Class for One Dimensional fitting.

See also:
OneDimensionalWeighted.

Member Function Documentation

double theplu::yat::regression::OneDimensional::chisq ( void   )  const

Chi-squared.

Chi-squared is defined as the $ \sum{(\hat{y_i}-y_i)^2} $

virtual void theplu::yat::regression::OneDimensional::fit ( const utility::VectorBase x,
const utility::VectorBase y 
) [pure virtual]

This function computes the best-fit given a model (see specific class for details) by minimizing $ \sum{(\hat{y_i}-y_i)^2} $, where $ \hat{y} $ is the fitted value.

Implemented in theplu::yat::regression::Linear, theplu::yat::regression::Naive, and theplu::yat::regression::Polynomial.

virtual double theplu::yat::regression::OneDimensional::predict ( const double  x  )  const [pure virtual]

Returns:
expected value in x accrding to the fitted model

Implemented in theplu::yat::regression::Linear, theplu::yat::regression::Naive, and theplu::yat::regression::Polynomial.

double theplu::yat::regression::OneDimensional::prediction_error2 ( const double  x  )  const

The prediction error is defined as the expected squared deviation a new data point will have from value the model provides: $ E(Y|x - \hat{y}(x))^2 $ and is typically divided into the conditional variance ( see s2() ) given $ x $ and the squared standard error ( see standard_error2() ) of the model estimation in $ x $.

Returns:
expected squared prediction error for a new data point in x

std::ostream& theplu::yat::regression::OneDimensional::print ( std::ostream &  os,
const double  min,
double  max,
const unsigned int  n 
) const

print output to ostream os

Printing estimated model to os in the points defined by min, max, and n. The values printed for each point is the x-value, the estimated y-value, and the estimated standard deviation of a new data poiunt will have from the y-value given the x-value (see prediction_error()).

Parameters:
os Ostream printout is sent to
n number of points printed
min smallest x-value for which the model is printed
max largest x-value for which the model is printed

double theplu::yat::regression::OneDimensional::r2 ( void   )  const

r2 is defined as $ 1 - \frac{Var(Y|x)}{Var(Y)} $ or the fraction of the variance explained by the regression model.

See also:
s2()

virtual double theplu::yat::regression::OneDimensional::s2 ( void   )  const [pure virtual]

virtual double theplu::yat::regression::OneDimensional::standard_error2 ( const double  x  )  const [pure virtual]

The standard error is defined as $ E(Y|x - \hat{y}(x))^2 $

Returns:
expected squared error of model value in x

Implemented in theplu::yat::regression::Linear, theplu::yat::regression::Naive, and theplu::yat::regression::Polynomial.

double theplu::yat::regression::OneDimensional::variance ( void   )  const [protected]

Variance of y


Member Data Documentation

Averager for pair of x and y

See also:
chisq()


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

Generated on Tue Jan 18 02:20:10 2011 for yat by  doxygen 1.5.5