logarithmic core More...

#include <core.h>

Inheritance diagram for logCore:

Public Member Functions
	logCore (const PsiData *data=NULL, const int sigmoid=1, const double alpha=0.1)
	construcor
	logCore (const logCore &original)
	copy constructor
double	g (double x, const std::vector< double > &prm) const throw (BadArgumentError)
	evaluate the core
double	dg (double x, const std::vector< double > &prm, int i) const
	evaluate derivative of the core
double	dgx (double x, const std::vector< double > &prm) const
	evaluate the first derivative of the core with respect to stimulus intensity
double	ddg (double x, const std::vector< double > &prm, int i, int j) const
	evaluate 2nd derivative of the core
double	inv (double y, const std::vector< double > &prm) const
	invert the core
double	dinv (double y, const std::vector< double > &prm, int i) const
	evaluate derivative of the inverse core with respect to parameter i
std::vector< double >	transform (int nprm, double a, double b) const
	transform parameters from a logistic regression model to starting values
PsiCore *	clone (void) const
	clone object by value
Static Public Member Functions
static std::string	getDescriptor (void)
	get a short string that identifies the type of core

Detailed Description

logarithmic core

The Weibull function typically gives a good fit for data from visual experiments. Unfortunately, the weibull distribution function does not allow for a straight forward fit using generalized linear models. However, the weibull distribution function is obtained if a gumbel is fit on logarithmic contrast values. This core is the same as the linearCore but for the logarithm of x

Constructor & Destructor Documentation

logCore::logCore	(	const PsiData *	data = `NULL`,
		const int	sigmoid = `1`,
		const double	alpha = `0.1`
	)

construcor

Parameters:

	data	use a data set to determine the correct scaling factors of initial values and initialize the objec
	sigmoid	ignored
	alpha	ignored

Member Function Documentation

double logCore::ddg	(	double	x,
		const std::vector< double > &	prm,
		int	i,
		int	j
	)			const `[inline, virtual]`

evaluate 2nd derivative of the core

Parameters:

	x	stimulus intensity
	prm	parameter vector
	i	first parameter with respect to which the derivative should be taken
	j	second parameter with respect to which the derivative should be taken

Reimplemented from PsiCore.

double logCore::dg	(	double	x,
		const std::vector< double > &	prm,
		int	i
	)			const `[virtual]`

evaluate derivative of the core

Parameters:

	x	stimulus intensity
	prm	parameter vector
	i	parameter with respect to which the derivative should evaluated

Reimplemented from PsiCore.

double logCore::dgx	(	double	x,
		const std::vector< double > &	prm
	)			const `[virtual]`

evaluate the first derivative of the core with respect to stimulus intensity

Parameters:

	x	stimulus intensity
	prm	parameter vector

Reimplemented from PsiCore.

double logCore::dinv	(	double	y,
		const std::vector< double > &	prm,
		int	i
	)			const `[virtual]`

evaluate derivative of the inverse core with respect to parameter i

Parameters:

	y	value at which to evaluate the inverse
	prm	parameter vector
	i	take derivative of the inverse core with respect to parameter i

Reimplemented from PsiCore.

double logCore::g	(	double	x,
		const std::vector< double > &	prm
	)			const throw (BadArgumentError) `[virtual]`

evaluate the core

Parameters:

	x	stimulus intensity
	prm	parameter vector

Reimplemented from PsiCore.

double logCore::inv	(	double	y,
		const std::vector< double > &	prm
	)			const `[inline, virtual]`

invert the core

Parameters:

	y	value at which to evaluate the inverse
	prm	parameter vector

Reimplemented from PsiCore.

std::vector< double > logCore::transform	(	int	nprm,
		double	a,
		double	b
	)			const `[virtual]`

transform parameters from a logistic regression model to starting values

Parameters:

	nprm	number of parameters in the final model
	a	intercept of the logistic regression model
	b	slope of the logistic regression model

Reimplemented from PsiCore.

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

src/core.h
src/core.cc

logCore Class Reference

Public Member Functions

Static Public Member Functions

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation