A TAxisGrow that has a label assigned to each bin and a bin width of 1.

While filling still works through coordinates (i.e. arrays of doubles), TAxisLabels allows to convert a string to a bin number or the bin's coordinate center. The number of labels and the number of bins reported by TAxisGrow might differ: the TAxisGrow will only grow when seeing a Fill(), while the TAxisLabels will add a new label whenever GetBinCenter() is called.

Implementation details: Filling happens often; GetBinCenter() needs to be fast. Thus the unordered_map. The painter needs the reverse: it wants the label for bin 0, bin 1 etc. The axis should only store the bin labels once; referencing them is (due to re-allocation, hashing etc) non-trivial. So instead, build a vector<string_view> for the few times the axis needs to be painted.

Definition at line 508 of file TAxis.h.

Public Member Functions
	TAxisLabels (const std::vector< std::string_view > &labels)
	Construct a TAxisLables from a `vector` of `string_view`s. More...

	TAxisLabels (const std::vector< std::string > &labels)
	Construct a TAxisLables from a `vector` of `string`s. More...

int	GetBinIndex (const std::string &label)
	Get the bin index with label. More...

double	GetBinCenter (const std::string &label)
	Get the center of the bin with label. More...

std::vector< std::string_view >	GetBinLabels () const
	Build a vector of labels. The position in the vector defines the label's bin. More...

Public Member Functions inherited from ROOT::TAxisGrow
constexpr	TAxisGrow (int nbins, double low, double high) noexcept
	Initialize a TAxisGrow. More...

int	Grow (int toBin)
	Grow this axis to make the "virtual bin" toBin in-range. More...

constexpr bool	CanGrow () const
	This axis kind can increase its range. More...

Public Member Functions inherited from ROOT::TAxisEquidistant
	TAxisEquidistant ()=default

constexpr	TAxisEquidistant (int nbins, double low, double high) noexcept
	Initialize a TAxisEquidistant. More...

constexpr int	FindBin (double x) const noexcept
	Find the bin index for the given coordinate. More...

double	GetMinimum () const noexcept
	Get the low end of the axis range. More...

double	GetMaximum () const noexcept
	Get the high end of the axis range. More...

double	GetBinWidth () const noexcept
	Get the width of the bins. More...

double	GetInverseBinWidth () const noexcept
	Get the inverse of the width of the bins. More...

double	GetBinCenter (int bin) const noexcept
	Get the bin center for the given bin index. More...

double	GetBinFrom (int bin) const noexcept
	Get the low bin border for the given bin index. More...

double	GetBinTo (int bin) const noexcept
	Get the high bin border for the given bin index. More...

int	GetBinIndexForLowEdge (double x) const noexcept
	If the coordinate `x` is a bin low edge (within 1E-6 of the coordinate), return the bin for which this is a low edge. More...

Public Member Functions inherited from ROOT::TAxisBase
constexpr	TAxisBase (int nbins) noexcept
	Construct a TAxisBase. More...

constexpr int	GetNBinsNoOver () const noexcept
	Get the number of bins, excluding under- and overflow. More...

constexpr int	GetNBins () const noexcept
	Get the number of bins, including under- and overflow. More...

constexpr int	GetUnderflowBin () const noexcept
	Get the bin index for the underflow bin. More...

constexpr int	GetOverflowBin () const noexcept
	Get the bin index for the underflow bin. More...

constexpr bool	IsUnderflowBin (int bin) const noexcept
	Whether the bin index is referencing a bin lower than the axis range. More...

constexpr bool	IsOverflowBin (int bin) const noexcept
	Whether the bin index is referencing a bin higher than the axis range. More...

const_iterator	begin () const noexcept
	Get a const_iterator pointing to the first non-underflow bin. More...

const_iterator	begin_with_underflow () const noexcept
	Get a const_iterator pointing the underflow bin. More...

const_iterator	end () const noexcept
	Get a const_iterator pointing right beyond the last non-overflow bin (i.e. More...

const_iterator	end_with_overflow () const noexcept
	Get a const_iterator pointing right beyond the overflow bin. More...

Private Attributes
std::unordered_map< std::string, int >	fLabelsIndex
	Map of label (view on `fLabels`'s elements) to bin index. More...

Additional Inherited Members
Public Types inherited from ROOT::TAxisBase
enum	EFindStatus { EFindStatus::kCanGrow, EFindStatus::kValid }
	Status of FindBin(x) More...

Static Public Member Functions inherited from ROOT::TAxisEquidistant
static constexpr bool	CanGrow () noexcept
	This axis cannot grow. More...

Static Public Attributes inherited from ROOT::TAxisBase
static constexpr const int	kIgnoreBin = -1
	FindBin() returns this bin to signal that the bin number is invalid. More...

static constexpr const int	kNOverflowBins [4] = {0, 1, 1, 2}
	Extra bins for each EAxisOverflow value. More...

Protected Member Functions inherited from ROOT::TAxisBase
constexpr int	AdjustOverflowBinNumber (int rawbin) const
	Given rawbin (<0 for underflow, >= GetNBinsNoOver() for overflow), determine the actual bin number taking into account how over/underflow should be handled. More...

	TAxisBase (const TAxisBase &)=default

	TAxisBase (TAxisBase &&)=default

TAxisBase &	operator= (const TAxisBase &)=default

TAxisBase &	operator= (TAxisBase &&)=default

Protected Attributes inherited from ROOT::TAxisEquidistant
double	fLow = 0.
	The lower limit of the axis. More...

double	fInvBinWidth = 0.
	The inverse of the bin width. More...

#include <ROOT/TAxis.h>

Inheritance diagram for ROOT::TAxisLabels:

Collaboration diagram for ROOT::TAxisLabels:

Constructor & Destructor Documentation

ROOT::TAxisLabels::TAxisLabels ( const std::vector< std::string_view > & labels )

inline

Construct a TAxisLables from a vector of string_views.

Definition at line 515 of file TAxis.h.

ROOT::TAxisLabels::TAxisLabels ( const std::vector< std::string > & labels )

inline

Construct a TAxisLables from a vector of strings.

Definition at line 522 of file TAxis.h.

Member Function Documentation

double ROOT::TAxisLabels::GetBinCenter ( const std::string & label )

inline

Get the center of the bin with label.

Definition at line 541 of file TAxis.h.

int ROOT::TAxisLabels::GetBinIndex ( const std::string & label )

inline

Get the bin index with label.

Definition at line 529 of file TAxis.h.

Referenced by GetBinCenter().

std::vector<std::string_view> ROOT::TAxisLabels::GetBinLabels ( ) const

inline

Build a vector of labels. The position in the vector defines the label's bin.

Definition at line 546 of file TAxis.h.

Referenced by ROOT::TAxisConfig::TAxisConfig().

Member Data Documentation

std::unordered_map<std::string, int > ROOT::TAxisLabels::fLabelsIndex

private

Map of label (view on fLabels's elements) to bin index.

Definition at line 511 of file TAxis.h.

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

hist/hist/v7/inc/ROOT/TAxis.h

Public Member Functions

Private Attributes

Additional Inherited Members

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation