A scale engine for logarithmic scales. More...

#include <qwt_scale_engine.h>

Inheritance diagram for QwtLogScaleEngine:

Public Member Functions
	QwtLogScaleEngine (uint base=10)
	Constructor.

virtual	~QwtLogScaleEngine ()
	Destructor.

virtual void	autoScale (int maxNumSteps, double &x1, double &x2, double &stepSize) const QWT_OVERRIDE
	Align and divide an interval.

virtual QwtScaleDiv	divideScale (double x1, double x2, int maxMajorSteps, int maxMinorSteps, double stepSize=0.0) const QWT_OVERRIDE
	Calculate a scale division for an interval.

Public Member Functions inherited from QwtScaleEngine
	QwtScaleEngine (uint base=10)
	Constructor.

virtual	~QwtScaleEngine ()
	Destructor.

void	setBase (uint base)
	Set the base of the scale engine.

uint	base () const

void	setAttribute (Attribute, bool on=true)
	Change a scale attribute.

bool	testAttribute (Attribute) const

void	setAttributes (Attributes)
	Change the scale attribute.

Attributes	attributes () const

void	setReference (double)
	Specify a reference point.

double	reference () const

void	setMargins (double lower, double upper)
	Specify margins at the scale's endpoints.

double	lowerMargin () const

double	upperMargin () const

void	setTransformation (QwtTransform *)
	Assign a transformation.

QwtTransform *	transformation () const
	Create and return a clone of the transformation of the engine.

Protected Member Functions
QwtInterval	align (const QwtInterval &, double stepSize) const
	Align an interval to a step size.

void	buildTicks (const QwtInterval &, double stepSize, int maxMinorSteps, QList< double > ticks[QwtScaleDiv::NTickTypes]) const
	Calculate ticks for an interval.

QList< double >	buildMajorTicks (const QwtInterval &interval, double stepSize) const
	Calculate major ticks for an interval.

void	buildMinorTicks (const QList< double > &majorTicks, int maxMinorSteps, double stepSize, QList< double > &minorTicks, QList< double > &mediumTicks) const
	Calculate minor/medium ticks for major ticks.

Protected Member Functions inherited from QwtScaleEngine
bool	contains (const QwtInterval &, double value) const
	Check if an interval "contains" a value.

QList< double >	strip (const QList< double > &, const QwtInterval &) const
	Remove ticks from a list, that are not inside an interval.

double	divideInterval (double intervalSize, int numSteps) const
	Calculate a step size for an interval size.

QwtInterval	buildInterval (double value) const
	Build an interval around a value.

Additional Inherited Members
Public Types inherited from QwtScaleEngine
enum	Attribute { NoAttribute = 0x00 , IncludeReference = 0x01 , Symmetric = 0x02 , Floating = 0x04 , Inverted = 0x08 }
	Layout attributes/布局属性 More...

Detailed Description

A scale engine for logarithmic scales.

The step size is measured in decades and the major step size will be adjusted to fit the pattern $\left\{ 1,2,3,5\right\} \cdot 10^{n}$ , where n is a natural number including zero.

Warning: the step size as well as the margins are measured in decades.

Constructor & Destructor Documentation

◆ QwtLogScaleEngine()

QwtLogScaleEngine::QwtLogScaleEngine ( uint base = 10 )

explicit

Constructor.

Parameters

base	Base of the scale engine

See also: setBase()

Member Function Documentation

◆ align()

QwtInterval QwtLogScaleEngine::align	(	const QwtInterval &	interval,
		double	stepSize
	)		const

protected

Align an interval to a step size.

The limits of an interval are aligned that both are integer multiples of the step size.

Parameters

interval	Interval
stepSize	Step size

Returns: Aligned interval

◆ autoScale()

void QwtLogScaleEngine::autoScale	(	int	maxNumSteps,
		double &	x1,
		double &	x2,
		double &	stepSize
	)		const

virtual

Align and divide an interval.

Parameters

maxNumSteps	Max. number of steps
x1	First limit of the interval (In/Out)
x2	Second limit of the interval (In/Out)
stepSize	Step size (Out)

See also: QwtScaleEngine::setAttribute()

Implements QwtScaleEngine.

◆ buildMajorTicks()

QList< double > QwtLogScaleEngine::buildMajorTicks	(	const QwtInterval &	interval,
		double	stepSize
	)		const

protected

Calculate major ticks for an interval.

Parameters

interval	Interval
stepSize	Step size

Returns: Calculated ticks

◆ buildMinorTicks()

void QwtLogScaleEngine::buildMinorTicks	(	const QList< double > &	majorTicks,
		int	maxMinorSteps,
		double	stepSize,
		QList< double > &	minorTicks,
		QList< double > &	mediumTicks
	)		const

protected

Calculate minor/medium ticks for major ticks.

Parameters

majorTicks	Major ticks
maxMinorSteps	Maximum number of minor steps
stepSize	Step size
minorTicks	Array to be filled with the calculated minor ticks
mediumTicks	Array to be filled with the calculated medium ticks

◆ buildTicks()

void QwtLogScaleEngine::buildTicks	(	const QwtInterval &	interval,
		double	stepSize,
		int	maxMinorSteps,
		QList< double >	ticks[QwtScaleDiv::NTickTypes]
	)		const

protected

Calculate ticks for an interval.

Parameters

interval	Interval
maxMinorSteps	Maximum number of minor steps
stepSize	Step size
ticks	Arrays to be filled with the calculated ticks

See also: buildMajorTicks(), buildMinorTicks

◆ divideScale()

QwtScaleDiv QwtLogScaleEngine::divideScale	(	double	x1,
		double	x2,
		int	maxMajorSteps,
		int	maxMinorSteps,
		double	stepSize = `0.0`
	)		const

virtual

Calculate a scale division for an interval.

Parameters

x1	First interval limit
x2	Second interval limit
maxMajorSteps	Maximum for the number of major steps
maxMinorSteps	Maximum number of minor steps
stepSize	Step size. If stepSize == 0, the engine calculates one.

Returns: Calculated scale division

Implements QwtScaleEngine.

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

/home/runner/work/QWT/QWT/src/qwt_scale_engine.h
/home/runner/work/QWT/QWT/src/qwt_scale_engine.cpp

Public Member Functions

Protected Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ QwtLogScaleEngine()

Member Function Documentation

◆ align()

◆ autoScale()

◆ buildMajorTicks()

◆ buildMinorTicks()

◆ buildTicks()

◆ divideScale()