A scale engine for logarithmic scales. More...

#include <qwt_scale_engine.h>

Inheritance diagram for QwtLogScaleEngine:

Public Member Functions
	QwtLogScaleEngine (uint base=10)

virtual	~QwtLogScaleEngine ()
	Destructor.

virtual void	autoScale (int maxSteps, double &x1, double &x2, double &stepSize) const

virtual QwtScaleDiv	divideScale (double x1, double x2, int numMajorSteps, int numMinorSteps, double stepSize=0.0) const
	Calculate a scale division for an interval. More...

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

virtual	~QwtScaleEngine ()
	Destructor.

void	setBase (uint base)

uint	base () const

void	setAttribute (Attribute, bool on=true)

bool	testAttribute (Attribute) const

void	setAttributes (Attributes)

Attributes	attributes () const

void	setReference (double reference)
	Specify a reference point. More...

double	reference () const

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

double	lowerMargin () const

double	upperMargin () const

void	setTransformation (QwtTransform *)

QwtTransform *	transformation () const

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

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

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

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

Protected Member Functions inherited from QwtScaleEngine
bool	contains (const QwtInterval &, double val) const

QList< double >	strip (const QList< double > &, const QwtInterval &) const

double	divideInterval (double interval, int numSteps) const

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

Additional Inherited Members
Public Types inherited from QwtScaleEngine
enum	Attribute { NoAttribute = 0x00, IncludeReference = 0x01, Symmetric = 0x02, Floating = 0x04, Inverted = 0x08 }

typedef QFlags< Attribute >	Attributes
	Layout attributes.

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 ( uint base = 10 )

Constructor

Parameters

base	Base of the scale engine

See Also: setBase()

Member Function Documentation

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

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.

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

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

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

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.

Public Member Functions

Protected Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation