Exponential-Gaussian hybrid distribution model for elution profiles. More...

#include <OpenMS/SIMULATION/EGHModel.h>

Inheritance diagram for EGHModel:

Public Types
typedef InterpolationModel::CoordinateType	CoordinateType
typedef Math::BasicStatistics < CoordinateType >	BasicStatistics
typedef LinearInterpolation::container_type	ContainerType
Public Member Functions
	EGHModel ()
	Default constructor.
	EGHModel (const EGHModel &source)
	copy constructor
virtual	~EGHModel ()
	destructor
virtual EGHModel &	operator= (const EGHModel &source)
	assignment operator
void	setOffset (CoordinateType offset)
	set offset without being computing all over and without any discrepancy
void	setSamples ()
	set sample/supporting points of interpolation
CoordinateType	getCenter () const
	get the center of the Gaussian model i.e. the position of the maximum
Static Public Member Functions
static BaseModel< 1 > *	create ()
	create new ElutionModel object (needed by Factory)
static const String	getProductName ()
	name of the model (needed by Factory)
Protected Member Functions
void	updateMembers_ ()
	This method is used to update extra member variables at the end of the setParameters() method.
void	computeBoundaries_ ()
	Computes a left & right boundary for the EGH Profile and sets the internal parameters accordingly.
void	evaluateEGH_ (CoordinateType &rt, CoordinateType &egh_value)
	Evaluate the EGH function at position rt.
Protected Attributes
CoordinateType	min_
CoordinateType	max_
BasicStatistics	statistics_
CoordinateType	height_
CoordinateType	apex_rt_
CoordinateType	A_
CoordinateType	B_
CoordinateType	tau_
CoordinateType	sigma_square_
CoordinateType	sigma_square_2_

Detailed Description

Exponential-Gaussian hybrid distribution model for elution profiles.

Lan K, Jorgenson JW. A hybrid of exponential and gaussian functions as a simple model of asymmetric chromatographic peaks. Journal of Chromatography A. 2001;915(1-2):1-13. Available at: http://linkinghub.elsevier.com/retrieve/pii/S0021967301005945

Parameters of this class are:

Name	Type	Default	Restrictions	Description
cutoff	float	0		Low intensity cutoff of the model. Peaks below this intensity are not considered part of the model.
interpolation_step	float	0.1		Sampling rate for the interpolation of the model function.
intensity_scaling	float	1		Scaling factor used to adjust the model distribution to the intensities of the data
statistics:mean	float	0		Centroid position of the model.
statistics:variance	float	1		The variance of the model.
egh:height	float	1000		Height of the exponential-Gaussian hybrid.
egh:retention	float	1200		Retention time of the exponential-Gaussian hybrid.
egh:guess_parameter	string	true	true, false	If set to true, the EGHModel will try to estimate the model parameters (tau and sigma-square) based on A,B, and alpha. If set to false, it will use the parameters tau and sigma-square directly.
egh:A	float	100		Horizontal distance between the vertical line at the peak maximum (H) and the leading line where the EGH has H*alpha (e.g. the left half-max for alpha=0.5).
egh:B	float	100		Horizontal distance between the vertical line at the peak maximum (H) and the trailing line where the EGH has H*alpha (e.g. the right half-max for alpha=0.5).
egh:alpha	float	0.5	min: 0 max: 1	See egh:A and egh:B.
egh:tau	float	0		Time constant of the exponential decay (tau is zero for gaussian peaks).
egh:sigma_square	float	1803.4	min: 0	Standard deviation of the peak.
bounding_box:compute	string	true	true, false	If true, the EGHModel will compute its own bounding box.
bounding_box:min	float	0		Lower end of bounding box enclosing the data used to fit the model.
bounding_box:max	float	0		Upper end of bounding box enclosing the data used to fit the model.

Note:

If a section name is documented, the documentation is displayed as tooltip.
Advanced parameter names are italic.

Member Typedef Documentation

typedef Math::BasicStatistics<CoordinateType> BasicStatistics

typedef LinearInterpolation::container_type ContainerType

typedef InterpolationModel::CoordinateType CoordinateType

Reimplemented from InterpolationModel.

Constructor & Destructor Documentation

EGHModel ( )

Default constructor.

EGHModel ( const EGHModel & source )

copy constructor

virtual ~EGHModel ( ) [virtual]

destructor

Member Function Documentation

void computeBoundaries_ ( ) [protected]

Computes a left & right boundary for the EGH Profile and sets the internal parameters accordingly.

static BaseModel<1>* create ( ) [inline, static]

create new ElutionModel object (needed by Factory)

void evaluateEGH_	(	CoordinateType &	rt,
		CoordinateType &	egh_value
	)			`[inline, protected]`

Evaluate the EGH function at position rt.

Parameters:

	rt	The position where the EGH function should be evaluated. Note that this is the position without the RT offset, meaning that the EGH apex is at position 0
	egh_value	The computed value

CoordinateType getCenter ( ) const [virtual]

get the center of the Gaussian model i.e. the position of the maximum

Reimplemented from InterpolationModel.

static const String getProductName ( ) [inline, static]

name of the model (needed by Factory)

Referenced by BaseModel< D >::registerChildren().

virtual EGHModel& operator= ( const EGHModel & source ) [virtual]