exp4kurve Class Reference

#include <imgclass.hpp>

Inheritance diagram for exp4kurve:

base refererrect $classeichkurve.html 9,18 76,42 [legend]

Detailed Description

Multi-exponential decay with 4 timescales.

exp4kurve is an eichkurve that uses four overlayed exponential decays with different timescales and weights for the absorption of non-monochromatic radiation. The formula is:

$I(x)=A\cdot \left[a_1 e^{-b_1 x} + a_2 e^{-b_2 x} + a_3 e^ {-b_3 x} + (1-a_1 -a_2-a_3) e^ {-b_4 x} \right]$

Definition at line 568 of file imgclass.hpp.


Public Member Functions
	exp4kurve (double sA, double sa1, double sa2, double sa3, double sb1, double sb2, double sb3, double sb4)
double	eichfun (double x) const
	Calibration function, which will be inverted.
double	deichfun_dx (double x) const
	Derivative of the calibration function.
double	initguess (bild16::data_t val) const
	Starting point for the iteration.
double	operator() (bild16::data_t val) const
	Conversion operator.
void	table_write (const char *name) const
	Write the lookup table to a file.
Protected Member Functions
double	fsolve (bild16::data_t val, double hmin, double hmax) const
void	table_init (double hmin, double hmax)
Protected Attributes
double *	lookup
Static Protected Attributes
static const char	magic [] = "EICHTABELLE"
Private Attributes
double	A
double	a1
double	a2
double	a3
double	b1
double	b2
double	b3
double	b4

Constructor & Destructor Documentation

exp4kurve::exp4kurve	(	double	sA,
		double	sa1,
		double	sa2,
		double	sa3,
		double	sb1,
		double	sb2,
		double	sb3,
		double	sb4
	)

Definition at line 491 of file imgclass.cpp.

References eichkurve::table_init().

Member Function Documentation

double exp4kurve::eichfun ( double x ) const [virtual]

Calibration function, which will be inverted.

Implements eichkurve.

Definition at line 499 of file imgclass.cpp.

References A, a1, a2, a3, b1, b2, b3, and b4.

double exp4kurve::deichfun_dx ( double x ) const [virtual]

Derivative of the calibration function.

Implements eichkurve.

Definition at line 503 of file imgclass.cpp.

References A, a1, a2, a3, b1, b2, b3, and b4.

double exp4kurve::initguess ( bild16::data_t val ) const [virtual]

Starting point for the iteration.

The implementation of initguess must return a starting value that triggers convergence to the solution. Otherwise table_init may hang.

Implements eichkurve.

Definition at line 508 of file imgclass.cpp.

References A, a3, and b3.

double eichkurve::operator() ( bild16::data_t val ) const [inline, inherited]

Conversion operator.

The function evaluation operator looks up an element in the lookup table and returns it. Initially, it was meant for usage such as:

        tablekurve tk("somecalib.data");
        bild16 bild("someimage.his");
        bildfloat bfl;

        MAP(bild) {
          bfl(y,x)=tk(bild(y,x));
        }

But because of point-wise float corrections necessary to overcome the deficiencies of the detector, it must now be applied to floating point images. bildfloat features a special member function for this purpose.

Definition at line 530 of file imgclass.hpp.

References eichkurve::lookup.

void eichkurve::table_write ( const char * name ) const [inherited]

Write the lookup table to a file.

Definition at line 462 of file imgclass.cpp.

References eichkurve::lookup, and eichkurve::magic.