A plot item, that represents a series of points. More...

#include <qwt_plot_curve.h>

Inheritance diagram for QwtPlotCurve:

Classes
class	PrivateData

Public Types
enum	CurveStyle { NoCurve = -1 , Lines , Sticks , Steps , Dots , UserCurve = 100 }
	Curve styles. More...

enum	CurveAttribute { Inverted = 0x01 , Fitted = 0x02 }
	Attribute for drawing the curve. More...

enum	LegendAttribute { LegendNoAttribute = 0x00 , LegendShowLine = 0x01 , LegendShowSymbol = 0x02 , LegendShowBrush = 0x04 }
	Attributes how to represent the curve on the legend. More...

enum	PaintAttribute { ClipPolygons = 0x01 , FilterPoints = 0x02 , MinimizeMemory = 0x04 , ImageBuffer = 0x08 , FilterPointsAggressive = 0x10 }
	Attributes to modify the drawing algorithm. More...

Public Types inherited from QwtPlotItem
enum	RttiValues { Rtti_PlotItem = 0 , Rtti_PlotGrid , Rtti_PlotScale , Rtti_PlotLegend , Rtti_PlotMarker , Rtti_PlotCurve , Rtti_PlotSpectroCurve , Rtti_PlotIntervalCurve , Rtti_PlotHistogram , Rtti_PlotSpectrogram , Rtti_PlotGraphic , Rtti_PlotTradingCurve , Rtti_PlotBarChart , Rtti_PlotMultiBarChart , Rtti_PlotShape , Rtti_PlotTextLabel , Rtti_PlotZone , Rtti_PlotVectorField , Rtti_PlotUserItem = 1000 }
	Runtime type information. More...

enum	ItemAttribute { Legend = 0x01 , AutoScale = 0x02 , Margins = 0x04 }
	Plot Item Attributes. More...

enum	ItemInterest { ScaleInterest = 0x01 , LegendInterest = 0x02 }
	Plot Item Interests/绘图项关注的事件类型 More...

enum	RenderHint { RenderAntialiased = 0x1 }
	Render hints. More...

Public Member Functions
	QwtPlotCurve (const QString &title=QString())
	Constructor.

	QwtPlotCurve (const QwtText &title)
	Constructor.

virtual	~QwtPlotCurve ()
	Destructor.

virtual int	rtti () const QWT_OVERRIDE

void	setPaintAttribute (PaintAttribute, bool on=true)
	Specify an attribute how to draw the curve.

bool	testPaintAttribute (PaintAttribute) const

void	setLegendAttribute (LegendAttribute, bool on=true)
	Specify an attribute how to draw the legend icon.

bool	testLegendAttribute (LegendAttribute) const

void	setLegendAttributes (LegendAttributes)
	Specify the attributes how to draw the legend icon.

LegendAttributes	legendAttributes () const

void	setRawSamples (const double xData, const double yData, int size)
	Initialize the data by pointing to memory blocks which are not managed by QwtPlotCurve.

void	setRawSamples (const float xData, const float yData, int size)
	Initialize the data by pointing to memory blocks which are not managed by QwtPlotCurve.

void	setRawSamples (const double *yData, int size)
	Initialize the data by pointing to a memory block which is not managed by QwtPlotCurve.

void	setRawSamples (const float *yData, int size)
	Initialize the data by pointing to memory blocks which are not managed by QwtPlotCurve.

void	setSamples (const double xData, const double yData, int size)
	Set data by copying x- and y-values from specified memory blocks.

void	setSamples (const float xData, const float yData, int size)
	Set data by copying x- and y-values from specified memory blocks.

void	setSamples (const double *yData, int size)
	Set data by copying y-values from a specified memory block.

void	setSamples (const float *yData, int size)
	Set data by copying y-values from a specified memory block.

void	setSamples (const QVector< double > &yData)
	Initialize data with an array of y values (explicitly shared)

void	setSamples (const QVector< float > &yData)
	Initialize data with an array of y values (explicitly shared)

void	setSamples (const QVector< double > &xData, const QVector< double > &yData)
	Initialize data with x- and y-arrays (explicitly shared)

void	setSamples (const QVector< float > &xData, const QVector< float > &yData)
	Initialize data with x- and y-arrays (explicitly shared)

void	setSamples (QVector< double > &&xData, QVector< double > &&yData)
	Initialize data with x- and y-arrays (explicitly shared)

void	setSamples (QVector< float > &&xData, QVector< float > &&yData)
	Initialize data with x- and y-arrays (explicitly shared)

void	setSamples (QVector< QPointF > &&)
	Initialize data with an array of points.

void	setSamples (const QVector< QPointF > &)
	Initialize data with an array of points.

void	setSamples (QwtSeriesData< QPointF > *)
	Assign a series of points.

virtual int	closestPoint (const QPointF &pos, double *dist=NULL) const
	Find the closest curve point for a specific position.

double	minXValue () const
	boundingRect().left()

double	maxXValue () const
	boundingRect().right()

double	minYValue () const
	boundingRect().top()

double	maxYValue () const
	boundingRect().bottom()

void	setCurveAttribute (CurveAttribute, bool on=true)
	Specify an attribute for drawing the curve.

bool	testCurveAttribute (CurveAttribute) const

void	setPen (const QColor &, qreal width=0.0, Qt::PenStyle=Qt::SolidLine)
	Build and assign a pen.

void	setPen (const QPen &)
	Assign a pen.

const QPen &	pen () const

void	setBrush (const QBrush &)
	Assign a brush.

const QBrush &	brush () const

void	setBaseline (double)
	Set the value of the baseline.

double	baseline () const

void	setStyle (CurveStyle style)
	Set the curve's drawing style.

CurveStyle	style () const

void	setSymbol (QwtSymbol *)
	Assign a symbol.

const QwtSymbol *	symbol () const

void	setCurveFitter (QwtCurveFitter *)
	Assign a curve fitter.

QwtCurveFitter *	curveFitter () const
	Get the curve fitter.

virtual void	drawSeries (QPainter *, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect, int from, int to) const QWT_OVERRIDE
	Draw an interval of the curve.

virtual QwtGraphic	legendIcon (int index, const QSizeF &) const QWT_OVERRIDE

Public Member Functions inherited from QwtPlotSeriesItem
	QwtPlotSeriesItem (const QString &title=QString())
	Constructor.

	QwtPlotSeriesItem (const QwtText &title)
	Constructor.

virtual	~QwtPlotSeriesItem ()
	Destructor.

void	setOrientation (Qt::Orientation)
	Set the orientation of the item.

Qt::Orientation	orientation () const

virtual void	draw (QPainter *, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect) const QWT_OVERRIDE
	Draw the complete series.

virtual QRectF	boundingRect () const QWT_OVERRIDE

virtual void	updateScaleDiv (const QwtScaleDiv &, const QwtScaleDiv &) QWT_OVERRIDE
	Update the item to changes of the axes scale division.

Public Member Functions inherited from QwtPlotItem
	QwtPlotItem ()
	Constructor.

	QwtPlotItem (const QString &title)
	Constructor.

	QwtPlotItem (const QwtText &title)
	Constructor.

virtual	~QwtPlotItem ()
	Destroy the QwtPlotItem.

void	attach (QwtPlot *plot)
	Attach the item to a plot.

void	detach ()
	This method detaches a QwtPlotItem from any QwtPlot it has been associated with.

QwtPlot *	plot () const
	Return attached plot.

void	setTitle (const QString &title)
	Set a new title.

void	setTitle (const QwtText &title)
	Set a new title.

const QwtText &	title () const

void	setItemAttribute (ItemAttribute, bool on=true)
	Toggle an item attribute.

bool	testItemAttribute (ItemAttribute) const
	Test an item attribute.

void	setItemInterest (ItemInterest, bool on=true)
	Toggle an item interest.

bool	testItemInterest (ItemInterest) const
	Test an item interest.

void	setRenderHint (RenderHint, bool on=true)
	Toggle an render hint.

bool	testRenderHint (RenderHint) const
	Test a render hint.

void	setRenderThreadCount (uint numThreads)
	On multi core systems rendering of certain plot item ( f.e QwtPlotRasterItem ) can be done in parallel in several threads.

uint	renderThreadCount () const

void	setLegendIconSize (const QSize &)
	Set the size of the legend icon.

QSize	legendIconSize () const

double	z () const
	Plot items are painted in increasing z-order.

void	setZ (double z)
	Set the z value.

void	show ()
	Show the item.

void	hide ()
	Hide the item.

virtual void	setVisible (bool)
	Show/Hide the item.

bool	isVisible () const

void	setAxes (QwtAxisId xAxis, QwtAxisId yAxis)
	Set X and Y axis.

void	setXAxis (QwtAxisId)
	Set the X axis.

QwtAxisId	xAxis () const
	Return xAxis.

void	setYAxis (QwtAxisId)
	Set the Y axis.

QwtAxisId	yAxis () const
	Return yAxis.

virtual void	itemChanged ()
	Update the legend and call QwtPlot::autoRefresh() for the parent plot.

virtual void	legendChanged ()
	Update the legend of the parent plot.

virtual void	getCanvasMarginHint (const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect, double &left, double &top, double &right, double &bottom) const
	Calculate a hint for the canvas margin.

virtual void	updateLegend (const QwtPlotItem *, const QList< QwtLegendData > &)
	Update the item to changes of the legend info.

QRectF	scaleRect (const QwtScaleMap &, const QwtScaleMap &) const
	Calculate the bounding scale rectangle of 2 maps.

QRectF	paintRect (const QwtScaleMap &, const QwtScaleMap &) const
	Calculate the bounding paint rectangle of 2 maps.

virtual QList< QwtLegendData >	legendData () const
	Return all information, that is needed to represent the item on the legend.

Public Member Functions inherited from QwtAbstractSeriesStore
virtual	~QwtAbstractSeriesStore ()
	Destructor.

Public Member Functions inherited from QwtSeriesStore< QPointF >
	QwtSeriesStore ()
	Constructor The store contains no series.

	~QwtSeriesStore ()
	Destructor.

void	setData (QwtSeriesData< QPointF > *series)
	Assign a series of samples.

QwtSeriesData< QPointF > *	data ()

const QwtSeriesData< QPointF > *	data () const

QPointF	sample (size_t index) const

virtual size_t	dataSize () const QWT_OVERRIDE

virtual QRectF	dataRect () const QWT_OVERRIDE

virtual void	setRectOfInterest (const QRectF &rect) QWT_OVERRIDE
	Set a the "rect of interest" for the series.

QwtSeriesData< QPointF > *	swapData (QwtSeriesData< QPointF > *series)
	Replace a series without deleting the previous one.

Protected Member Functions
void	init ()
	Initialize internal members.

virtual void	drawCurve (QPainter *, int style, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect, int from, int to) const
	Draw the line part (without symbols) of a curve interval.

virtual void	drawSymbols (QPainter *, const QwtSymbol &, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect, int from, int to) const
	Draw symbols.

virtual void	drawLines (QPainter *, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect, int from, int to) const
	Draw lines.

virtual void	drawSticks (QPainter *, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect, int from, int to) const
	Draw sticks.

virtual void	drawDots (QPainter *, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect, int from, int to) const
	Draw dots.

virtual void	drawSteps (QPainter *, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect, int from, int to) const
	Draw step function.

virtual void	fillCurve (QPainter *, const QwtScaleMap &, const QwtScaleMap &, const QRectF &canvasRect, QPolygonF &) const
	Fill the area between the curve and the baseline with the curve brush.

void	closePolyline (QPainter *, const QwtScaleMap &, const QwtScaleMap &, QPolygonF &) const
	Complete a polygon to be a closed polygon including the area between the original polygon and the baseline.

Protected Member Functions inherited from QwtPlotSeriesItem
virtual void	dataChanged () QWT_OVERRIDE
	dataChanged() indicates, that the series has been changed.

Protected Member Functions inherited from QwtPlotItem
QwtGraphic	defaultIcon (const QBrush &, const QSizeF &) const
	Return a default icon from a brush.

Detailed Description

A plot item, that represents a series of points.

A curve is the representation of a series of points in the x-y plane. It supports different display styles, interpolation ( f.e. spline ) and symbols.

Usage

a) Assign curve properties: When a curve is created, it is configured to draw black solid lines with in QwtPlotCurve::Lines style and no symbols. You can change this by calling setPen(), setStyle() and setSymbol().
b) Connect/Assign data.: QwtPlotCurve gets its points using a QwtSeriesData object offering a bridge to the real storage of the points ( like QAbstractItemModel ). There are several convenience classes derived from QwtSeriesData, that also store the points inside ( like QStandardItemModel ). QwtPlotCurve also offers a couple of variations of setSamples(), that build QwtSeriesData objects from arrays internally.
c) Attach the curve to a plot: See QwtPlotItem::attach()

Example:: see examples/bode

See also: QwtPointSeriesData, QwtSymbol, QwtScaleMap

Member Enumeration Documentation

◆ CurveAttribute

enum QwtPlotCurve::CurveAttribute

Attribute for drawing the curve.

See also: setCurveAttribute(), testCurveAttribute(), curveFitter()

Enumerator

Inverted

For QwtPlotCurve::Steps only.

Draws a step function from the right to the left.

Fitted

Only in combination with QwtPlotCurve::Lines A QwtCurveFitter tries to interpolate/smooth the curve, before it is painted.

Note: Curve fitting requires temporary memory for calculating coefficients and additional points. If painting in QwtPlotCurve::Fitted mode is slow it might be better to fit the points, before they are passed to QwtPlotCurve.

◆ CurveStyle

enum QwtPlotCurve::CurveStyle

Curve styles.

See also: setStyle(), style()

Enumerator
NoCurve	Don't draw a curve. Note: This doesn't affect the symbols.
Lines	Connect the points with straight lines. The lines might be interpolated depending on the 'Fitted' attribute. Curve fitting can be configured using setCurveFitter().
Sticks	Draw vertical or horizontal sticks ( depending on the orientation() ) from a baseline which is defined by setBaseline().
Steps	Connect the points with a step function. The step function is drawn from the left to the right or vice versa, depending on the QwtPlotCurve::Inverted attribute.
Dots	Draw dots at the locations of the data points. Note: This is different from a dotted line (see setPen()), and faster as a curve in QwtPlotCurve::NoStyle style and a symbol painting a point.
UserCurve	Styles >= QwtPlotCurve::UserCurve are reserved for derived classes of QwtPlotCurve that overload drawCurve() with additional application specific curve types.

◆ LegendAttribute

enum QwtPlotCurve::LegendAttribute

Attributes how to represent the curve on the legend.

See also: setLegendAttribute(), testLegendAttribute(), QwtPlotItem::legendData(), legendIcon()

Enumerator
LegendNoAttribute	QwtPlotCurve tries to find a color representing the curve and paints a rectangle with it.
LegendShowLine	If the style() is not QwtPlotCurve::NoCurve a line is painted with the curve pen().
LegendShowSymbol	If the curve has a valid symbol it is painted.
LegendShowBrush	If the curve has a brush a rectangle filled with the curve brush() is painted.

◆ PaintAttribute

enum QwtPlotCurve::PaintAttribute

Attributes to modify the drawing algorithm.

The default setting enables ClipPolygons | FilterPoints

See also: setPaintAttribute(), testPaintAttribute()

Enumerator
ClipPolygons	Clip polygons before painting them. In situations, where points are far outside the visible area (f.e when zooming deep) this might be a substantial improvement for the painting performance
FilterPoints	Tries to reduce the data that has to be painted, by sorting out duplicates, or paintings outside the visible area. Might have a notable impact on curves with many close points. Only a couple of very basic filtering algorithms are implemented.
MinimizeMemory	Minimize memory usage that is temporarily needed for the translated points, before they get painted. This might slow down the performance of painting
ImageBuffer	Render the points to a temporary image and paint the image. This is a very special optimization for Dots style, when having a huge amount of points. With a reasonable number of points QPainter::drawPoints() will be faster.
FilterPointsAggressive	More aggressive point filtering trying to filter out intermediate points, accepting minor visual differences. Has only an effect, when drawing the curve to a paint device in integer coordinates ( f.e. all widgets on screen ) using the fact, that consecutive points are often mapped to the same x or y coordinate. Each chunk of samples mapped to the same coordinate can be reduced to 4 points ( first, min, max last ). In the worst case the polygon to be rendered will be 4 times the width of the plot canvas. The algorithm is very fast and effective for huge datasets, and can be used inside a replot cycle. Note Implemented for QwtPlotCurve::Lines only As this algo replaces many small lines by a long one a nasty bug of the raster paint engine ( Qt 4.8, Qt 5.1 - 5.3 ) becomes more dominant. For these versions the bug can be worked around by enabling the QwtPainter::polylineSplitting() mode.

Constructor & Destructor Documentation

◆ QwtPlotCurve() [1/2]

QwtPlotCurve::QwtPlotCurve ( const QString & title = QString() )

explicit

Constructor.

Parameters

title Title of the curve

◆ QwtPlotCurve() [2/2]

QwtPlotCurve::QwtPlotCurve ( const QwtText & title )

explicit

Constructor.

Parameters

title Title of the curve

Member Function Documentation

◆ baseline()

double QwtPlotCurve::baseline ( ) const

Returns: Value of the baseline

See also: setBaseline()

◆ brush()

const QBrush & QwtPlotCurve::brush ( ) const

Returns: Brush used to fill the area between lines and the baseline

See also: setBrush(), setBaseline(), baseline()

◆ closePolyline()

void QwtPlotCurve::closePolyline	(	QPainter *	painter,
		const QwtScaleMap &	xMap,
		const QwtScaleMap &	yMap,
		QPolygonF &	polygon
	)		const

protected

Complete a polygon to be a closed polygon including the area between the original polygon and the baseline.

Parameters

painter	Painter
xMap	X map
yMap	Y map
polygon	Polygon to be completed

◆ closestPoint()

int QwtPlotCurve::closestPoint	(	const QPointF &	pos,
		double *	dist = `NULL`
	)		const

virtual

Find the closest curve point for a specific position.

Parameters

pos	Position, where to look for the closest curve point
dist	If dist != NULL, closestPoint() returns the distance between the position and the closest curve point

Returns: Index of the closest curve point, or -1 if none can be found ( f.e when the curve has no points )

Note: closestPoint() implements a dumb algorithm, that iterates over all points

◆ curveFitter()

QwtCurveFitter * QwtPlotCurve::curveFitter ( ) const

Get the curve fitter.

If curve fitting is disabled NULL is returned.

Returns: Curve fitter

See also: setCurveFitter(), Fitted

◆ drawCurve()

void QwtPlotCurve::drawCurve	(	QPainter *	painter,
		int	style,
		const QwtScaleMap &	xMap,
		const QwtScaleMap &	yMap,
		const QRectF &	canvasRect,
		int	from,
		int	to
	)		const

protectedvirtual

Draw the line part (without symbols) of a curve interval.

Parameters

painter	Painter
style	curve style, see QwtPlotCurve::CurveStyle
xMap	x map
yMap	y map
canvasRect	Contents rectangle of the canvas
from	index of the first point to be painted
to	index of the last point to be painted

See also: draw(), drawDots(), drawLines(), drawSteps(), drawSticks()

◆ drawDots()

void QwtPlotCurve::drawDots	(	QPainter *	painter,
		const QwtScaleMap &	xMap,
		const QwtScaleMap &	yMap,
		const QRectF &	canvasRect,
		int	from,
		int	to
	)		const

protectedvirtual

Draw dots.

Parameters

painter	Painter
xMap	x map
yMap	y map
canvasRect	Contents rectangle of the canvas
from	index of the first point to be painted
to	index of the last point to be painted

See also: draw(), drawCurve(), drawSticks(), drawLines(), drawSteps()

◆ drawLines()

void QwtPlotCurve::drawLines	(	QPainter *	painter,
		const QwtScaleMap &	xMap,
		const QwtScaleMap &	yMap,
		const QRectF &	canvasRect,
		int	from,
		int	to
	)		const

protectedvirtual

Draw lines.

If the CurveAttribute Fitted is enabled a QwtCurveFitter tries to interpolate/smooth the curve, before it is painted.

Parameters

painter	Painter
xMap	x map
yMap	y map
canvasRect	Contents rectangle of the canvas
from	index of the first point to be painted
to	index of the last point to be painted

See also: setCurveAttribute(), setCurveFitter(), draw(), drawLines(), drawDots(), drawSteps(), drawSticks()

◆ drawSeries()

void QwtPlotCurve::drawSeries	(	QPainter *	painter,
		const QwtScaleMap &	xMap,
		const QwtScaleMap &	yMap,
		const QRectF &	canvasRect,
		int	from,
		int	to
	)		const

virtual

Draw an interval of the curve.

Parameters

painter	Painter
xMap	Maps x-values into pixel coordinates.
yMap	Maps y-values into pixel coordinates.
canvasRect	Contents rectangle of the canvas
from	Index of the first point to be painted
to	Index of the last point to be painted. If to < 0 the curve will be painted to its last point.

See also: drawCurve(), drawSymbols(),

Implements QwtPlotSeriesItem.

◆ drawSteps()

void QwtPlotCurve::drawSteps	(	QPainter *	painter,
		const QwtScaleMap &	xMap,
		const QwtScaleMap &	yMap,
		const QRectF &	canvasRect,
		int	from,
		int	to
	)		const

protectedvirtual

Draw step function.

The direction of the steps depends on Inverted attribute.

Parameters

painter	Painter
xMap	x map
yMap	y map
canvasRect	Contents rectangle of the canvas
from	index of the first point to be painted
to	index of the last point to be painted

See also: CurveAttribute, setCurveAttribute(), draw(), drawCurve(), drawDots(), drawLines(), drawSticks()

◆ drawSticks()

void QwtPlotCurve::drawSticks	(	QPainter *	painter,
		const QwtScaleMap &	xMap,
		const QwtScaleMap &	yMap,
		const QRectF &	canvasRect,
		int	from,
		int	to
	)		const

protectedvirtual

Draw sticks.

Parameters

painter	Painter
xMap	x map
yMap	y map
canvasRect	Contents rectangle of the canvas
from	index of the first point to be painted
to	index of the last point to be painted

See also: draw(), drawCurve(), drawDots(), drawLines(), drawSteps()

◆ drawSymbols()

void QwtPlotCurve::drawSymbols	(	QPainter *	painter,
		const QwtSymbol &	symbol,
		const QwtScaleMap &	xMap,
		const QwtScaleMap &	yMap,
		const QRectF &	canvasRect,
		int	from,
		int	to
	)		const

protectedvirtual

Draw symbols.

Parameters

painter	Painter
symbol	Curve symbol
xMap	x map
yMap	y map
canvasRect	Contents rectangle of the canvas
from	Index of the first point to be painted
to	Index of the last point to be painted

See also: setSymbol(), drawSeries(), drawCurve()

◆ fillCurve()

void QwtPlotCurve::fillCurve	(	QPainter *	painter,
		const QwtScaleMap &	xMap,
		const QwtScaleMap &	yMap,
		const QRectF &	canvasRect,
		QPolygonF &	polygon
	)		const

protectedvirtual

Fill the area between the curve and the baseline with the curve brush.

Parameters

painter	Painter
xMap	x map
yMap	y map
canvasRect	Contents rectangle of the canvas
polygon	Polygon - will be modified !

See also: setBrush(), setBaseline(), setStyle()

◆ legendAttributes()

QwtPlotCurve::LegendAttributes QwtPlotCurve::legendAttributes ( ) const

Returns: Attributes how to draw the legend icon

See also: setLegendAttributes(), testLegendAttribute()

◆ legendIcon()

QwtGraphic QwtPlotCurve::legendIcon	(	int	index,
		const QSizeF &	size
	)		const

virtual

Returns: Icon representing the curve on the legend

Parameters

index	Index of the legend entry ( ignored as there is only one )
size	Icon size

See also: QwtPlotItem::setLegendIconSize(), QwtPlotItem::legendData()

Reimplemented from QwtPlotItem.

◆ pen()

const QPen & QwtPlotCurve::pen ( ) const

Returns: Pen used to draw the lines

See also: setPen(), brush()

◆ rtti()

int QwtPlotCurve::rtti ( ) const

virtual

Returns: QwtPlotItem::Rtti_PlotCurve

Reimplemented from QwtPlotItem.

◆ setBaseline()

void QwtPlotCurve::setBaseline ( double value )

Set the value of the baseline.

The baseline is needed for filling the curve with a brush or the Sticks drawing style.

The interpretation of the baseline depends on the orientation(). With Qt::Vertical, the baseline is interpreted as a horizontal line at y = baseline(), with Qt::Horizontal, it is interpreted as a vertical line at x = baseline().

The default value is 0.0.

Parameters

value Value of the baseline

See also: baseline(), setBrush(), setStyle(), QwtPlotAbstractSeriesItem::orientation()

◆ setBrush()

void QwtPlotCurve::setBrush ( const QBrush & brush )

Assign a brush.

In case of brush.style() != QBrush::NoBrush and style() != QwtPlotCurve::Sticks the area between the curve and the baseline will be filled.

In case !brush.color().isValid() the area will be filled by pen.color(). The fill algorithm simply connects the first and the last curve point to the baseline. So the curve data has to be sorted (ascending or descending).

Parameters

brush New brush

See also: brush(), setBaseline(), baseline()

◆ setCurveAttribute()

void QwtPlotCurve::setCurveAttribute	(	CurveAttribute	attribute,
		bool	on = `true`
	)

Specify an attribute for drawing the curve.

Parameters

attribute	Curve attribute
on	On/Off

/sa testCurveAttribute(), setCurveFitter()

◆ setCurveFitter()

void QwtPlotCurve::setCurveFitter ( QwtCurveFitter * curveFitter )

Assign a curve fitter.

The curve fitter "smooths" the curve points, when the Fitted CurveAttribute is set. setCurveFitter(NULL) also disables curve fitting.

The curve fitter operates on the translated points ( = widget coordinates) to be functional for logarithmic scales. Obviously this is less performant for fitting algorithms, that reduce the number of points.

For situations, where curve fitting is used to improve the performance of painting huge series of points it might be better to execute the fitter on the curve points once and to cache the result in the QwtSeriesData object.

Parameters

curveFitter() Curve fitter

See also: Fitted

◆ setLegendAttribute()

void QwtPlotCurve::setLegendAttribute	(	LegendAttribute	attribute,
		bool	on = `true`
	)

Specify an attribute how to draw the legend icon.

Parameters

attribute	Attribute
on	On/Off /sa testLegendAttribute(). legendIcon()

◆ setLegendAttributes()

void QwtPlotCurve::setLegendAttributes ( LegendAttributes attributes )

Specify the attributes how to draw the legend icon.

Parameters

attributes Attributes /sa setLegendAttribute(). legendIcon()

◆ setPaintAttribute()

void QwtPlotCurve::setPaintAttribute	(	PaintAttribute	attribute,
		bool	on = `true`
	)

Specify an attribute how to draw the curve.

Parameters

attribute	Paint attribute
on	On/Off

See also: testPaintAttribute()

◆ setPen() [1/2]

void QwtPlotCurve::setPen	(	const QColor &	color,
		qreal	width = `0.0`,
		Qt::PenStyle	style = `Qt::SolidLine`
	)

Build and assign a pen.

In Qt5 the default pen width is 1.0 ( 0.0 in Qt4 ) what makes it non cosmetic ( see QPen::isCosmetic() ). This method has been introduced to hide this incompatibility.

Parameters

color	Pen color
width	Pen width
style	Pen style

See also: pen(), brush()

◆ setPen() [2/2]

void QwtPlotCurve::setPen ( const QPen & pen )

Assign a pen.

Parameters

pen New pen

See also: pen(), brush()

◆ setRawSamples() [1/4]

void QwtPlotCurve::setRawSamples	(	const double *	xData,
		const double *	yData,
		int	size
	)

Initialize the data by pointing to memory blocks which are not managed by QwtPlotCurve.

setRawSamples is provided for efficiency. It is important to keep the pointers during the lifetime of the underlying QwtCPointerData class.

Parameters

xData	pointer to x data
yData	pointer to y data
size	size of x and y

See also: QwtCPointerData

◆ setRawSamples() [2/4]

void QwtPlotCurve::setRawSamples	(	const double *	yData,
		int	size
	)

Initialize the data by pointing to a memory block which is not managed by QwtPlotCurve.

The memory contains the y coordinates, while the index is interpreted as x coordinate.

setRawSamples() is provided for efficiency. It is important to keep the pointers during the lifetime of the underlying QwtCPointerValueData class.

Parameters

yData	pointer to y data
size	size of x and y

See also: QwtCPointerData

◆ setRawSamples() [3/4]

void QwtPlotCurve::setRawSamples	(	const float *	xData,
		const float *	yData,
		int	size
	)

Initialize the data by pointing to memory blocks which are not managed by QwtPlotCurve.

setRawSamples is provided for efficiency. It is important to keep the pointers during the lifetime of the underlying QwtCPointerData class.

Parameters

xData	pointer to x data
yData	pointer to y data
size	size of x and y

See also: QwtCPointerData

◆ setRawSamples() [4/4]

void QwtPlotCurve::setRawSamples	(	const float *	yData,
		int	size
	)

Initialize the data by pointing to memory blocks which are not managed by QwtPlotCurve.

The memory contains the y coordinates, while the index is interpreted as x coordinate.

setRawSamples() is provided for efficiency. It is important to keep the pointers during the lifetime of the underlying QwtCPointerValueData class.

Parameters

yData	pointer to y data
size	size of x and y

See also: QwtCPointerData

◆ setSamples() [1/13]

void QwtPlotCurve::setSamples	(	const double *	xData,
		const double *	yData,
		int	size
	)

Set data by copying x- and y-values from specified memory blocks.

Contrary to setRawSamples(), this function makes a 'deep copy' of the data.

Parameters

xData	pointer to x values
yData	pointer to y values
size	size of xData and yData

See also: QwtPointArrayData

◆ setSamples() [2/13]

void QwtPlotCurve::setSamples	(	const double *	yData,
		int	size
	)

Set data by copying y-values from a specified memory block.

The memory contains the y coordinates, while the index is interpreted as x coordinate.

Parameters

yData	y data
size	size of yData

See also: QwtValuePointData

◆ setSamples() [3/13]

void QwtPlotCurve::setSamples	(	const float *	xData,
		const float *	yData,
		int	size
	)

Set data by copying x- and y-values from specified memory blocks.

Contrary to setRawSamples(), this function makes a 'deep copy' of the data.

Parameters

xData	pointer to x values
yData	pointer to y values
size	size of xData and yData

See also: QwtPointArrayData

◆ setSamples() [4/13]

void QwtPlotCurve::setSamples	(	const float *	yData,
		int	size
	)

Set data by copying y-values from a specified memory block.

The vector contains the y coordinates, while the index is interpreted as x coordinate.

Parameters

yData	y data
size	size of yData

See also: QwtValuePointData

◆ setSamples() [5/13]

void QwtPlotCurve::setSamples	(	const QVector< double > &	xData,
		const QVector< double > &	yData
	)

Initialize data with x- and y-arrays (explicitly shared)

Parameters

xData	x data
yData	y data

See also: QwtPointArrayData

◆ setSamples() [6/13]

void QwtPlotCurve::setSamples ( const QVector< double > & yData )

Initialize data with an array of y values (explicitly shared)

The vector contains the y coordinates, while the index is the x coordinate.

Parameters

yData y data

See also: QwtValuePointData

◆ setSamples() [7/13]

void QwtPlotCurve::setSamples	(	const QVector< float > &	xData,
		const QVector< float > &	yData
	)

Initialize data with x- and y-arrays (explicitly shared)

Parameters

xData	x data
yData	y data

See also: QwtPointArrayData

◆ setSamples() [8/13]

void QwtPlotCurve::setSamples ( const QVector< float > & yData )

Initialize data with an array of y values (explicitly shared)

The vector contains the y coordinates, while the index is the x coordinate.

Parameters

yData y data

See also: QwtValuePointData

◆ setSamples() [9/13]

void QwtPlotCurve::setSamples ( const QVector< QPointF > & samples )

Initialize data with an array of points.

Parameters

samples Vector of points

Note: QVector is implicitly shared; QPolygonF is derived from QVector<QPointF>

◆ setSamples() [10/13]

void QwtPlotCurve::setSamples	(	QVector< double > &&	xData,
		QVector< double > &&	yData
	)

Initialize data with x- and y-arrays (explicitly shared)

Parameters

xData	x data
yData	y data

See also: QwtPointArrayData

◆ setSamples() [11/13]

void QwtPlotCurve::setSamples	(	QVector< float > &&	xData,
		QVector< float > &&	yData
	)

Initialize data with x- and y-arrays (explicitly shared)

Parameters

xData	x data
yData	y data

See also: QwtPointArrayData

◆ setSamples() [12/13]

void QwtPlotCurve::setSamples ( QVector< QPointF > && samples )

Initialize data with an array of points.

Parameters

samples Vector of points

Note: QVector is implicitly shared; QPolygonF is derived from QVector<QPointF>

◆ setSamples() [13/13]

void QwtPlotCurve::setSamples ( QwtSeriesData< QPointF > * data )

Assign a series of points.

setSamples() is just a wrapper for setData() without any additional value - beside that it is easier to find for the developer.

Parameters

data Data

Warning: The item takes ownership of the data object, deleting it when its not used anymore.

◆ setStyle()

void QwtPlotCurve::setStyle ( CurveStyle style )

Set the curve's drawing style.

Parameters

style Curve style

See also: style()

◆ setSymbol()

void QwtPlotCurve::setSymbol ( QwtSymbol * symbol )

Assign a symbol.

The curve will take the ownership of the symbol, hence the previously set symbol will be delete by setting a new one. If symbol is NULL no symbol will be drawn.

Parameters

symbol Symbol

See also: symbol()

◆ style()

QwtPlotCurve::CurveStyle QwtPlotCurve::style ( ) const

Returns: Style of the curve

See also: setStyle()

◆ symbol()

const QwtSymbol * QwtPlotCurve::symbol ( ) const

Returns: Current symbol or NULL, when no symbol has been assigned

See also: setSymbol()

◆ testCurveAttribute()

bool QwtPlotCurve::testCurveAttribute ( CurveAttribute attribute ) const

Returns: true, if attribute is enabled

See also: setCurveAttribute()

◆ testLegendAttribute()

bool QwtPlotCurve::testLegendAttribute ( LegendAttribute attribute ) const

Returns: True, when attribute is enabled

See also: setLegendAttribute()

◆ testPaintAttribute()

bool QwtPlotCurve::testPaintAttribute ( PaintAttribute attribute ) const

Returns: True, when attribute is enabled

See also: setPaintAttribute()

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

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

Classes

Public Types

Public Member Functions

Protected Member Functions

Detailed Description

Member Enumeration Documentation

◆ CurveAttribute

◆ CurveStyle

◆ LegendAttribute

◆ PaintAttribute

Constructor & Destructor Documentation

◆ QwtPlotCurve() [1/2]

◆ QwtPlotCurve() [2/2]

Member Function Documentation

◆ baseline()

◆ brush()

◆ closePolyline()

◆ closestPoint()

◆ curveFitter()

◆ drawCurve()

◆ drawDots()

◆ drawLines()

◆ drawSeries()

◆ drawSteps()

◆ drawSticks()

◆ drawSymbols()

◆ fillCurve()

◆ legendAttributes()

◆ legendIcon()

◆ pen()

◆ rtti()

◆ setBaseline()

◆ setBrush()

◆ setCurveAttribute()

◆ setCurveFitter()

◆ setLegendAttribute()

◆ setLegendAttributes()

◆ setPaintAttribute()

◆ setPen() [1/2]

◆ setPen() [2/2]

◆ setRawSamples() [1/4]

◆ setRawSamples() [2/4]

◆ setRawSamples() [3/4]

◆ setRawSamples() [4/4]

◆ setSamples() [1/13]

◆ setSamples() [2/13]

◆ setSamples() [3/13]

◆ setSamples() [4/13]

◆ setSamples() [5/13]

◆ setSamples() [6/13]

◆ setSamples() [7/13]

◆ setSamples() [8/13]

◆ setSamples() [9/13]

◆ setSamples() [10/13]

◆ setSamples() [11/13]

◆ setSamples() [12/13]

◆ setSamples() [13/13]

◆ setStyle()

◆ setSymbol()

◆ style()

◆ symbol()

◆ testCurveAttribute()

◆ testLegendAttribute()

◆ testPaintAttribute()