expkurve Class Reference

#include <imgclass.hpp>

Inheritance diagram for expkurve:

base refererrect $classeichkurve.html 6,18 73,42 [legend]

Detailed Description

Multi-exponential decay with 3 timescales.

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

$I(x)=A\cdot \left[f_1 e^{-g_1 x} + f_2 e^{-g_2 x} + (1-f_1 -f_2) e^ {-g_3 x} \right]$

Definition at line 543 of file imgclass.hpp.


Public Member Functions
	expkurve (double sA, double sg1, double sg2, double sg3, double sf1, double sf2)
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	g1
double	g2
double	g3
double	f1
double	f2

Constructor & Destructor Documentation

expkurve::expkurve	(	double	sA,
		double	sg1,
		double	sg2,
		double	sg3,
		double	sf1,
		double	sf2
	)

Definition at line 470 of file imgclass.cpp.

References eichkurve::table_init().

Member Function Documentation

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

Calibration function, which will be inverted.

Implements eichkurve.

Definition at line 477 of file imgclass.cpp.

References A, f1, f2, g1, g2, and g3.

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

Derivative of the calibration function.

Implements eichkurve.

Definition at line 481 of file imgclass.cpp.

References A, f1, f2, g1, g2, and g3.

double expkurve::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 486 of file imgclass.cpp.

References A, and g1.

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.