a-b parameterization of the psychometric function More...
#include <core.h>
Public Member Functions | |
| abCore (const PsiData *data=NULL, const int sigmoid=1, const double alpha=0.1) | |
| construcor | |
| abCore (const abCore &original) | |
| copy construcor | |
| double | g (double x, const std::vector< double > &prm) const |
| evaluate the core of the sigmoid | |
| double | dg (double x, const std::vector< double > &prm, int i) const |
| evaluate the first derivative of the core with respect to parameter i | |
| 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 the second derivative of the core with respect to parameters i and j | |
| double | inv (double y, const std::vector< double > &prm) const |
| invert the core | |
| double | dinv (double p, const std::vector< double > &prm, int i) const |
| 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 the parameters used here | |
| 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
a-b parameterization of the psychometric function
In the original psignifit release, the nonlinearity was usually defined as a cumulative distribution function. In that case two parameters describing the mean alpha and the standard deviation beta of this distribution were required. This yielded a core object of the form (x-alpha)/beta. This type of internal parameterization is implemented here.
The parameter vector is in any case expected to have the first two parameters alpha and beta
Constructor & Destructor Documentation
| abCore::abCore | ( | const PsiData * | data = NULL, |
|
| const int | sigmoid = 1, |
|||
| const double | alpha = 0.1 | |||
| ) | [inline] |
construcor
- Parameters:
-
data ignored sigmoid ignored alpha ignored
Member Function Documentation
| double abCore::ddg | ( | double | x, | |
| const std::vector< double > & | prm, | |||
| int | i, | |||
| int | j | |||
| ) | const [virtual] |
evaluate the second derivative of the core with respect to parameters i and j
- Parameters:
-
x stimulus intensity prm parameter vector i index of the parameter to which the first derivative should be evaluated j index of the parameter to which the second derivative should be evaluated
Reimplemented from PsiCore.
| double abCore::dg | ( | double | x, | |
| const std::vector< double > & | prm, | |||
| int | i | |||
| ) | const [virtual] |
evaluate the first derivative of the core with respect to parameter i
- Parameters:
-
x stimulus intensity prm parameter vector i index of the parameter to which the derivative should be evaluated
Reimplemented from PsiCore.
| double abCore::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 abCore::dinv | ( | double | p, | |
| const std::vector< double > & | prm, | |||
| int | i | |||
| ) | const [virtual] |
derivative of the inverse core with respect to parameter i
- Parameters:
-
p transformed intenstiy at which to evaluate the derivative prm parameter vector i evaluate the derivative with respect to parameter i
Reimplemented from PsiCore.
| double abCore::g | ( | double | x, | |
| const std::vector< double > & | prm | |||
| ) | const [inline, virtual] |
evaluate the core of the sigmoid
- Parameters:
-
x stimulus intensity prm parameter vector
Reimplemented from PsiCore.
| double abCore::inv | ( | double | y, | |
| const std::vector< double > & | prm | |||
| ) | const [virtual] |
invert the core
- Parameters:
-
y transformed intensity prm parameter vector
Reimplemented from PsiCore.
| std::vector< double > abCore::transform | ( | int | nprm, | |
| double | a, | |||
| double | b | |||
| ) | const [virtual] |
transform parameters from a logistic regression model to the parameters used here
- Parameters:
-
nprm number of parameters in the final parameter vector 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
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