QwtSyntheticPointData类 参考

Synthetic point data 更多...

#include <qwt_point_data.h>

类 QwtSyntheticPointData 继承关系图:

Public 成员函数
	QwtSyntheticPointData (size_t size, const QwtInterval &=QwtInterval())
	Constructor
void	setSize (size_t size)
	Change the number of points
virtual size_t	size () const override
	Get the number of points
void	setInterval (const QwtInterval &)
	Set the bounding interval
QwtInterval	interval () const
	Get the bounding interval
virtual QRectF	boundingRect () const override
	Calculate the bounding rectangle
virtual QPointF	sample (size_t index) const override
	Calculate the point from an index
virtual double	y (double x) const =0
virtual double	x (size_t index) const
	Calculate a x-value from an index
virtual void	setRectOfInterest (const QRectF &) override
	Set the "rectangle of interest"
QRectF	rectOfInterest () const
	Get the "rectangle of interest"
Public 成员函数 继承自 QwtPointSeriesData
	QwtPointSeriesData (const QVector< QPointF > &=QVector< QPointF >())
	Constructor
Public 成员函数 继承自 QwtArraySeriesData< QPointF >
	QwtArraySeriesData ()
	Constructor
	QwtArraySeriesData (const QVector< QPointF > &samples)
	Constructor
	QwtArraySeriesData (QVector< QPointF > &&samples)
void	setSamples (const QVector< QPointF > &samples)
	Assign an array of samples
void	setSamples (QVector< QPointF > &&samples)
const QVector< QPointF >	samples () const
Public 成员函数 继承自 QwtSeriesData< T >
	QwtSeriesData ()
	Constructor
virtual	~QwtSeriesData ()
	Destructor

额外继承的成员函数
Protected 属性 继承自 QwtArraySeriesData< QPointF >
QVector< QPointF >	m_samples
	Vector of samples
Protected 属性 继承自 QwtSeriesData< T >
QRectF	cachedBoundingRect
	Can be used to cache a calculated bounding rectangle

详细描述

Synthetic point data

QwtSyntheticPointData provides a fixed number of points for an interval. The points are calculated in equidistant steps in x-direction.

If the interval is invalid, the points are calculated for the "rectangle of interest", what normally is the displayed area on the plot canvas. In this mode you get different levels of detail, when zooming in/out.

Example

The following example shows how to implement a sinus curve.

#include <cmath>
#include <qwt_series_data.h>
#include <qwt_plot_curve.h>
#include <qwt_plot.h>
#include <qapplication.h>
 
class SinusData: public QwtSyntheticPointData
{
public:
 SinusData():
     QwtSyntheticPointData( 100 )
 {
 }
 
 virtual double y( double x ) const
 {
     return qSin( x );
 }
};
 
int main(int argc, char **argv)
{
 QApplication a( argc, argv );
 
 QwtPlot plot;
 plot.setAxisScale( QwtAxis::XBottom, 0.0, 10.0 );
 plot.setAxisScale( QwtAxis::YLeft, -1.0, 1.0 );
 
 QwtPlotCurve *curve = new QwtPlotCurve( "y = sin(x)" );
 curve->setData( new SinusData() );
 curve->attach( &plot );
 
 plot.show();
 return a.exec();
}

构造及析构函数说明

QwtSyntheticPointData()

QwtSyntheticPointData::QwtSyntheticPointData	(	size_t	size,
		const QwtInterval &	interval = QwtInterval()
	)

Constructor

参数

[in]	size	Number of points
[in]	interval	Bounding interval for the points

参见

setInterval(), setSize()

成员函数说明

boundingRect()

QRectF QwtSyntheticPointData::boundingRect ( ) const

overridevirtual

Calculate the bounding rectangle

This implementation iterates over all points, which could often be implemented much faster using the characteristics of the series. When there are many points it is recommended to overload and reimplement this method using the characteristics of the series (if possible).

返回

Bounding rectangle

重载 QwtPointSeriesData .

interval()

QwtInterval QwtSyntheticPointData::interval

(

)

const

Get the bounding interval

返回

Bounding interval

参见

setInterval(), size()

rectOfInterest()

QRectF QwtSyntheticPointData::rectOfInterest

(

)

const

Get the "rectangle of interest"

返回

Rectangle of interest

参见

setRectOfInterest()

sample()

QPointF QwtSyntheticPointData::sample ( size_t  index ) const

overridevirtual

Calculate the point from an index

参数

[in]

index

Index

返回

QPointF(x(index), y(x(index)))

警告

For invalid indices (index < 0 || index >= size()) (0, 0) is returned.

重载 QwtArraySeriesData< QPointF > .

setInterval()

void QwtSyntheticPointData::setInterval

(

const QwtInterval &

interval

)

Set the bounding interval

参数

[in]

interval

Interval

参见

interval(), setSize()

setRectOfInterest()

void QwtSyntheticPointData::setRectOfInterest ( const QRectF &  rect )

overridevirtual

Set the "rectangle of interest"

QwtPlotSeriesItem defines the current area of the plot canvas as "rect of interest" ( QwtPlotSeriesItem::updateScaleDiv() ). If interval().isValid() == false the x values are calculated in the interval rect.left() -> rect.right().

参数

[in]

rect

Rectangle of interest

参见

rectOfInterest()

重载 QwtSeriesData< T > .

setSize()

void QwtSyntheticPointData::setSize

(

size_t

size

)

Change the number of points

参数

[in]

size

Number of points

参见

size(), setInterval()

size()

size_t QwtSyntheticPointData::size ( ) const

overridevirtual

Get the number of points

返回

Number of points

参见

setSize(), interval()

重载 QwtArraySeriesData< QPointF > .

x()

double QwtSyntheticPointData::x ( size_t  index ) const

virtual

Calculate a x-value from an index

x values are calculated by dividing an interval into equidistant steps. If !interval().isValid() the interval is calculated from the "rectangle of interest".

参数

[in]

index

Index of the requested point

返回

Calculated x coordinate

参见

interval(), rectOfInterest(), y()

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该类的文档由以下文件生成:

• /home/runner/work/QWT/QWT/src/core/qwt_point_data.h
• /home/runner/work/QWT/QWT/src/core/qwt_point_data.cpp