#include <AlphaS.h>

Inheritance diagram for LHAPDF::AlphaS_Ipol:

Public Member Functions
std::string	type () const
	Implementation type of this solver.

double	alphasQ2 (double q2) const
	Calculate alphaS(Q2)

void	setQValues (const std::vector< double > &qs)

void	setQ2Values (const std::vector< double > &q2s)

void	setAlphaSValues (const std::vector< double > &as)

Public Member Functions inherited from LHAPDF::AlphaS
	AlphaS ()
	Base class constructor for default param setup.

virtual	~AlphaS ()
	Destructor.

double	alphasQ (double q) const
	Calculate alphaS(Q)

int	numFlavorsQ (double q) const
	Calculate the number of active flavours at energy scale Q.

virtual int	numFlavorsQ2 (double q2) const
	Calculate the number of active flavours at energy scale Q2.

double	quarkMass (int id) const
	Get a quark mass by PDG code.

void	setQuarkMass (int id, double value)
	Set quark masses by PDG code.

double	quarkThreshold (int id) const
	Get a flavor scale threshold by PDG code.

void	setQuarkThreshold (int id, double value)
	Set a flavor threshold by PDG code (= quark masses by default)

int	orderQCD ()

void	setOrderQCD (int order)
	Set the order of QCD (expressed as number of loops)

void	setMZ (double mz)
	Set the Z mass used in this alpha_s.

void	setAlphaSMZ (double alphas)
	Set the alpha_s(MZ) used in this alpha_s.

void	setMassReference (double mref)
	Set the Z mass used in this alpha_s.

void	setAlphaSReference (double alphas)
	Set the alpha_s(MZ) used in this alpha_s.

virtual void	setLambda (unsigned int, double)
	Set the {i}th Lambda constant for i active flavors.

void	setFlavorScheme (FlavorScheme scheme, int nf=-1)
	Set flavor scheme of alpha_s solver.

FlavorScheme	flavorScheme () const
	Get flavor scheme.

Private Member Functions
double	_interpolateCubic (double T, double VL, double VDL, double VH, double VDH) const
	Standard cubic interpolation formula.

double	_ddq_central (size_t i) const
	Get the gradient for a patch in the middle of the grid.

double	_ddq_forward (size_t i) const
	Get the gradient for a patch at the low end of the grid.

double	_ddq_backward (size_t i) const
	Get the gradient for a patch at the high end of the grid.

void	_setup_grids () const

Private Attributes
std::map< double, AlphaSArray >	_knotarrays

std::vector< double >	_q2s
	Array of ipol knots in Q2.

std::vector< double >	_as
	Array of alpha_s values for the Q2 knots.

Additional Inherited Members
Public Types inherited from LHAPDF::AlphaS
enum	FlavorScheme { FIXED , VARIABLE }
	Enum of flavor schemes.

Protected Member Functions inherited from LHAPDF::AlphaS
double	_beta (int i, int nf) const

std::vector< double >	_betas (int nf) const

Protected Attributes inherited from LHAPDF::AlphaS
int	_qcdorder
	Order of QCD evolution (expressed as number of loops)

double	_mz
	Mass of the Z boson in GeV.

double	_alphas_mz
	Value of alpha_s(MZ)

double	_mreference
	Reference mass in GeV.

double	_alphas_reference
	Value of alpha_s(reference mass)

bool	_customref
	Decides whether to use custom reference values or fall back on MZ/AlphaS_MZ.

std::map< int, double >	_quarkmasses

std::map< int, double >	_flavorthresholds

FlavorScheme	_flavorscheme
	The flavor scheme in use.

int	_fixflav
	The allowed numbers of flavours in a fixed scheme.

Detailed Description

Interpolate alpha_s from tabulated points in Q2 via metadata

Todo: Extrapolation: log-gradient xpol at low Q, const at high Q?

Examples: /tests/testalphas.cc.

Member Function Documentation

◆ _setup_grids()

void LHAPDF::AlphaS_Ipol::_setup_grids ( ) const

private

Synchronise the contents of the single Q2 / alpha_s vectors into subgrid objects

Note: This is const so it can be called silently from a const method

◆ alphasQ2()

double LHAPDF::AlphaS_Ipol::alphasQ2 ( double q2 ) const

virtual

Calculate alphaS(Q2)

Implements LHAPDF::AlphaS.

◆ setAlphaSValues()

void LHAPDF::AlphaS_Ipol::setAlphaSValues ( const std::vector< double > & as )

inline

Set the array of alpha_s(Q2) values for interpolation

The supplied vector must match the layout of Q2 knots. Subgrids may have discontinuities, i.e. different alpha_s values on either side of a subgrid boundary (for the same Q values).

Examples: /tests/testalphas.cc.

◆ setQ2Values()

void LHAPDF::AlphaS_Ipol::setQ2Values ( const std::vector< double > & q2s )

inline

Set the array of Q2 values for interpolation

Subgrids are represented by repeating the values which are the end of one subgrid and the start of the next. The supplied vector must match the layout of alpha_s values.

◆ setQValues()

void LHAPDF::AlphaS_Ipol::setQValues ( const std::vector< double > & qs )

Set the array of Q values for interpolation

Writes to the same internal arrays as setQ2Values, appropriately transformed.

Examples: /tests/testalphas.cc.

◆ type()

std::string LHAPDF::AlphaS_Ipol::type ( ) const

inlinevirtual

Implementation type of this solver.

Implements LHAPDF::AlphaS.

Member Data Documentation

◆ _knotarrays

std::map<double, AlphaSArray> LHAPDF::AlphaS_Ipol::_knotarrays

mutableprivate

Map of AlphaSArrays "binned" for lookup by low edge in (log)Q2

Note: This is mutable so it can be initialized silently from a const method

The documentation for this class was generated from the following file:

/home/andy/proj/hep/lhapdf6/include/LHAPDF/AlphaS.h

Public Member Functions

Private Member Functions

Private Attributes

Additional Inherited Members