Base class for scale engines. Más...

#include <qwt_scale_engine.h>

Diagrama de herencias de QwtScaleEngine

Clases
class	PrivateData
Tipos públicos
enum	Attribute { NoAttribute = 0, IncludeReference = 1, Symmetric = 2, Floating = 4, Inverted = 8 }
	see QwtScaleEngine::setAttribute, testAttribute Más...
Métodos públicos
	QwtScaleEngine ()
	Ctor.
virtual	~QwtScaleEngine ()
	Dtor.
void	setAttribute (Attribute, bool on=true)
bool	testAttribute (Attribute) const
void	setAttributes (int)
int	attributes () const
void	setReference (double reference)
	Specify a reference point.
double	reference () const
void	setMargins (double m1, double m2)
	Specify margins at the scale's endpoints.
double	loMargin () const
double	hiMargin () const
virtual void	autoScale (int maxNumSteps, double &x1, double &x2, double &stepSize) const =0
virtual QwtScaleDiv	divideScale (double x1, double x2, int maxMajSteps, int maxMinSteps, double stepSize=0.0) const =0
	Calculate a scale division.
virtual QwtScaleTransformation *	transformation () const =0
Métodos protegidos
bool	contains (const QwtDoubleInterval &, double val) const
QwtValueList	strip (const QwtValueList &, const QwtDoubleInterval &) const
double	divideInterval (double interval, int numSteps) const
QwtDoubleInterval	buildInterval (double v) const
	Build an interval for a value.

Descripción detallada

Base class for scale engines.

A scale engine trys to find "reasonable" ranges and step sizes for scales.

The layout of the scale can be varied with setAttribute().

Qwt offers implementations for logarithmic (log10) and linear scales. Contributions for other types of scale engines (date/time, log2 ... ) are welcome.

Documentación de las enumeraciones miembro de la clase

enum QwtScaleEngine::Attribute

see QwtScaleEngine::setAttribute, testAttribute

Valores de enumeraciones:

NoAttribute
IncludeReference
Symmetric
Floating
Inverted

Documentación del constructor y destructor

QwtScaleEngine::QwtScaleEngine ( ) [explicit]

Ctor.

QwtScaleEngine::~QwtScaleEngine ( ) [virtual]

Dtor.

Documentación de las funciones miembro

int QwtScaleEngine::attributes ( ) const

Return the scale attributes

virtual void QwtScaleEngine::autoScale	(	int	maxNumSteps,
		double &	x1,
		double &	x2,
		double &	stepSize
	)		const `[pure virtual]`

Align and divide an interval

Parámetros:

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

Implementado en QwtLinearScaleEngine y QwtLog10ScaleEngine.

QwtDoubleInterval QwtScaleEngine::buildInterval ( double v ) const [protected]

Build an interval for a value.

In case of v == 0.0 the interval is [-0.5, 0.5], otherwide it is [0.5 * v, 1.5 * v]

bool QwtScaleEngine::contains	(	const QwtDoubleInterval &	interval,
		double	value
	)		const `[protected]`

Check if an interval "contains" a value

Parámetros:

interval	Interval
value	Value

Ver también:: QwtScaleArithmetic::compareEps

double QwtScaleEngine::divideInterval	(	double	intervalSize,
		int	numSteps
	)		const `[protected]`

Calculate a step size for an interval size

Parámetros:

intervalSize	Interval size
numSteps	Number of steps

Devuelve:: Step size

virtual QwtScaleDiv QwtScaleEngine::divideScale	(	double	x1,
		double	x2,
		int	maxMajSteps,
		int	maxMinSteps,
		double	stepSize = `0.0`
	)		const `[pure virtual]`

Calculate a scale division.

Parámetros:

x1	First interval limit
x2	Second interval limit
maxMajSteps	Maximum for the number of major steps
maxMinSteps	Maximum number of minor steps
stepSize	Step size. If stepSize == 0.0, the scaleEngine calculates one.

Implementado en QwtLinearScaleEngine y QwtLog10ScaleEngine.

double QwtScaleEngine::hiMargin ( ) const

Devuelve:: the margin at the upper end of the scale The default margin is 0.

Ver también:: QwtScaleEngine::setMargins()

double QwtScaleEngine::loMargin ( ) const

Devuelve:: the margin at the lower end of the scale The default margin is 0.

Ver también:: QwtScaleEngine::setMargins()

double QwtScaleEngine::reference ( ) const

Devuelve:: the reference value

Ver también:: QwtScaleEngine::setReference(), QwtScaleEngine::setAttribute()

void QwtScaleEngine::setAttribute	(	Attribute	attribute,
		bool	on = `true`
	)

Change a scale attribute

Parámetros:

attribute	Attribute to change
on	On/Off

The behaviour of the scale engine can be changed with the following attributes:

QwtScaleEngine::IncludeReference: Build a scale which includes the reference value.
QwtScaleEngine::Symmetric: Build a scale which is symmetric to the reference value.
QwtScaleEngine::Floating: The endpoints of the scale are supposed to be equal the outmost included values plus the specified margins (see setMargins()). If this attribute is not* set, the endpoints of the scale will be integer multiples of the step size.
QwtScaleEngine::Inverted: Turn the scale upside down.

Ver también:: QwtScaleEngine::testAttribute()

void QwtScaleEngine::setAttributes ( int attributes )

Change the scale attribute

Parámetros:

attributes Set scale attributes

Ver también:: QwtScaleEngine::attributes()

void QwtScaleEngine::setMargins	(	double	mlo,
		double	mhi
	)

Specify margins at the scale's endpoints.

Parámetros:

mlo	minimum distance between the scale's lower boundary and the smallest enclosed value
mhi	minimum distance between the scale's upper boundary and the greatest enclosed value

Margins can be used to leave a minimum amount of space between the enclosed intervals and the boundaries of the scale.

Atención:

QwtLog10ScaleEngine measures the margins in decades.

Ver también:: QwtScaleEngine::hiMargin, QwtScaleEngine::loMargin

void QwtScaleEngine::setReference ( double r )

Specify a reference point.

Parámetros:

r	new reference value

The reference point is needed if options IncludeRef or Symmetric are active. Its default value is 0.0.

QwtValueList QwtScaleEngine::strip	(	const QwtValueList &	ticks,
		const QwtDoubleInterval &	interval
	)		const `[protected]`

Remove ticks from a list, that are not inside an interval

Parámetros:

ticks	Tick list
interval	Interval

Devuelve:: Stripped tick list

bool QwtScaleEngine::testAttribute ( Attribute attribute ) const

Check if a attribute is set.

Parámetros:

attribute Attribute to be tested

Ver también:: QwtScaleEngine::setAttribute() for a description of the possible options.

virtual QwtScaleTransformation* QwtScaleEngine::transformation ( ) const [pure virtual]

Devuelve:: a transformation

Implementado en QwtLinearScaleEngine y QwtLog10ScaleEngine.

La documentación para esta clase fue generada a partir de los siguientes ficheros:

src/qwt/src/qwt_scale_engine.h
src/qwt/src/qwt_scale_engine.cpp

Clases

Tipos públicos

Métodos públicos

Métodos protegidos

Descripción detallada

Documentación de las enumeraciones miembro de la clase

Documentación del constructor y destructor

Documentación de las funciones miembro