QwtLogScaleEngine Class Reference

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 maxNumSteps, double &x1, double &x2, double &stepSize) const override
virtual QwtScaleDiv	divideScale (double x1, double x2, int maxMajorSteps, int maxMinorSteps, double stepSize=0.0) const override
	Calculate a scale division for an interval.
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)
	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 *)
QwtTransform *	transformation () const

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
QList< double >	strip (const QList< double > &, const QwtInterval &) const
double	divideInterval (double intervalSize, int numSteps) const
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 }
typedef QFlags< Attribute >	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 , where n is a natural number including zero.

Warning

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

Definition at line 191 of file qwt_scale_engine.h.

Constructor & Destructor Documentation

QwtLogScaleEngine()

QwtLogScaleEngine::QwtLogScaleEngine ( uint base = 10 )

explicit

Constructor

Parameters

base	Base of the scale engine

See also

setBase()

Definition at line 776 of file qwt_scale_engine.cpp.

~QwtLogScaleEngine()

QwtLogScaleEngine::~QwtLogScaleEngine ( )

virtual

Destructor.

Definition at line 783 of file qwt_scale_engine.cpp.

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

Definition at line 1106 of file qwt_scale_engine.cpp.

autoScale()

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

overridevirtual

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.

Definition at line 797 of file qwt_scale_engine.cpp.

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

Definition at line 967 of file qwt_scale_engine.cpp.

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

Definition at line 1002 of file qwt_scale_engine.cpp.

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

Definition at line 940 of file qwt_scale_engine.cpp.

divideScale()

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

overridevirtual

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.

Definition at line 879 of file qwt_scale_engine.cpp.