XSecStat is a concrete helper class used to collect statistics about the cross section for a specific process or group of processes. More...

#include <XSecStat.h>

Public Types
enum	{ plainWeights = 0, plainVetoedWeights, reweightedWeights, reweightedVetoedWeights }
	Enumerate the different weight classes.

Public Member Functions
Standard constructors, destructor and assignment operator.
	XSecStat ()
	The default constructor.

	XSecStat (CrossSection xsecmax)
	Constructor taking the overestimated cross section, xsecmax, as argument.

XSecStat &	operator= (const XSecStat &x)=default
	The assignment operator.

XSecStat &	operator+= (const XSecStat &x)
	Add the contents of another XSecStat.

void	reset ()
	Reset the statistics.

Simple access functions
void	accept ()
	An event of the corresponding class has been accepted. More...

void	select (double weight)
	An event of the corresponding class has been attempted. More...

void	reweight (double oldWeight, double newWeight)
	Reweight a selected and accepted event.

void	reject (double weight=1.0)
	Reject the event which was last accepted with accept() or selected with select(double). More...

CrossSection	maxXSec () const
	The overestimated cross section.

double	sumWeights () const
	The sum of the weights so far.

double	sumWeights2 () const
	The sum of the squared weights so far.

double	sumWeightsNoReweight () const
	The sum of the weights so far, excluding reweighting.

double	sumWeights2NoReweight () const
	The sum of the squared weights so far, excluding reweighting.

CrossSection	xSec (double att=0) const
	The current estimate of the cross section for the corresponding class of events. More...

CrossSection	xSecErr (double att=0) const
	The current estimate of the error in the cross section for the corresponding class of events. More...

CrossSection	xSecNoReweight (double att=0) const
	The current estimate of the cross section for the corresponding class of events, excluding reweighting. More...

CrossSection	xSecErrNoReweight (double att=0) const
	The current estimate of the error in the cross section for the corresponding class of events, excluding reweighting. More...

double	attempts () const
	Number of attempts so far.

double	accepted () const
	Number of accepts so far.

double	vetoed () const
	Number of vetoes so far.

void	maxXSec (CrossSection x)
	Set the overestimated cross section.

I/O functions
void	output (PersistentOStream &os) const
	Output to a persistent stream.

void	input (PersistentIStream &is)
	Input from a persistent stream.

Private Attributes
CrossSection	theMaxXSec
	The overestimated cross section.

double	theAttempts
	Number of attempts so far.

double	theAccepted
	Number of accepted events so far.

double	theVetoed
	Number of events vetoed after being accepted.

array< double, 4 >	theSumWeights
	The sum of the weights so far.

array< double, 4 >	theSumWeights2
	The sum of the squared weights so far.

double	theLastWeight
	The last selected weight, ignoring reweighting.

Detailed Description

XSecStat is a concrete helper class used to collect statistics about the cross section for a specific process or group of processes.

It contains an overestimated cross section and information about the number of times the process has been used to generate an event and how many times this event has been accepted.

An object of this class must initially be given an overestimated cross section in the constructor or with the maxXSec(CrossSection) function. Each time the corresponding process is selected (according to maxXSec()), the select(double) function should be called giving the weight with which the event will be accepted as argument. If the event is then accepted, the accept() function should be called. If an event is later vetoed, the reject() function should be called.

Definition at line 36 of file XSecStat.h.

Member Function Documentation

◆ accept()

void ThePEG::XSecStat::accept ( )

inline

An event of the corresponding class has been accepted.

The select() method must have been called before.

Definition at line 109 of file XSecStat.h.

References theAccepted.

Referenced by ThePEG::StandardXComb::accept(), and ThePEG::LesHouchesReader::accept().

◆ reject()

void ThePEG::XSecStat::reject ( double weight = 1.0 )

inline

Reject the event which was last accepted with accept() or selected with select(double).

The weight should be set to the value, $w$ , used in the previous call to select(double), except if the event has been accepted with the probability $w$ , in which case weight should be set to $sign(1, w)$ .