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 638 of file TAxis.hxx.

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...

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

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

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

int	GetBinIndex (const std::string &label)
	Get the bin index 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::Experimental::TAxisGrow
	TAxisGrow (std::string_view title, int nbins, double low, double high) noexcept
	Initialize a TAxisGrow. More...

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

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

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

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

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

	TAxisEquidistant (std::string_view title, int nbinsNoOver, double low, double high) noexcept
	Initialize a TAxisEquidistant. More...

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

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...

double	GetBinTo (int bin) const noexcept
	Get the high bin border for the given bin index. 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	GetMaximum () const noexcept
	Get the high end of the axis range. More...

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

Public Member Functions inherited from ROOT::Experimental::TAxisBase
	TAxisBase (int nbinsNoOver, bool canGrow) noexcept
	Construct a TAxisBase. More...

	TAxisBase (std::string_view title, int nbinsNoOver, bool canGrow) noexcept
	Construct a TAxisBase. More...

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

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

int	GetNOverflowBins () const noexcept
	Get the number of over- and underflow bins: 0 for growable axes, 2 otherwise. More...

int	GetOverflowBin () const noexcept
	Get the bin index for the underflow bin (or the next bin outside range if CanGrow()). More...

const std::string &	GetTitle () const

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

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

bool	IsUnderflowBin (int bin) const noexcept
	Whether the bin index is referencing a bin lower 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::Experimental::TAxisBase
enum	EFindStatus { EFindStatus::kCanGrow, EFindStatus::kValid }
	Status of FindBin(x) More...

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

Static Public Attributes inherited from ROOT::Experimental::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::Experimental::TAxisEquidistant
	TAxisEquidistant (int nbinsNoOver, double low, double high, bool canGrow) noexcept
	Initialize a TAxisEquidistant. More...

	TAxisEquidistant (std::string_view title, int nbinsNoOver, double low, double high, bool canGrow) noexcept
	Initialize a TAxisEquidistant. More...

Protected Member Functions inherited from ROOT::Experimental::TAxisBase
	TAxisBase ()
	Default construct a TAxisBase (for use by derived classes for I/O) More...

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

Static Protected Member Functions inherited from ROOT::Experimental::TAxisEquidistant
static double	GetInvBinWidth (int nbinsNoOver, double lowOrHigh, double highOrLow)
	Determine the inverse bin width. More...

Protected Attributes inherited from ROOT::Experimental::TAxisEquidistant
double	fInvBinWidth = 0.
	The inverse of the bin width. More...

double	fLow = 0.
	The lower limit of the axis. More...

#include <ROOT/TAxis.hxx>

Inheritance diagram for ROOT::Experimental::TAxisLabels:

[legend]

Constructor & Destructor Documentation

◆ TAxisLabels() [1/4]

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

inlineexplicit

Construct a TAxisLables from a vector of string_views.

Definition at line 645 of file TAxis.hxx.

◆ TAxisLabels() [2/4]

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

inlineexplicit

Construct a TAxisLables from a vector of strings.

Definition at line 652 of file TAxis.hxx.

◆ TAxisLabels() [3/4]

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

inlineexplicit

Construct a TAxisLables from a vector of string_views, with title.

Definition at line 659 of file TAxis.hxx.

◆ TAxisLabels() [4/4]

ROOT::Experimental::TAxisLabels::TAxisLabels	(	std::string_view	title,
		const std::vector< std::string > &	labels
	)

inlineexplicit

Construct a TAxisLables from a vector of strings, with title.

Definition at line 666 of file TAxis.hxx.

Member Function Documentation

◆ GetBinCenter()

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

inline

Get the center of the bin with label.

Definition at line 685 of file TAxis.hxx.

◆ GetBinIndex()

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

inline

Get the bin index with label.

Definition at line 673 of file TAxis.hxx.

◆ GetBinLabels()

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

inline

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

Definition at line 690 of file TAxis.hxx.

Member Data Documentation

◆ fLabelsIndex

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

private

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

Definition at line 641 of file TAxis.hxx.

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

hist/hist/v7/inc/ROOT/TAxis.hxx

Public Member Functions

Private Attributes

Additional Inherited Members

Constructor & Destructor Documentation

◆ TAxisLabels() [1/4]

◆ TAxisLabels() [2/4]

◆ TAxisLabels() [3/4]

◆ TAxisLabels() [4/4]

Member Function Documentation

◆ GetBinCenter()

◆ GetBinIndex()

◆ GetBinLabels()

Member Data Documentation

◆ fLabelsIndex