QwtPlotCurve Class Reference

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

#include <qwt_plot_curve.h>

Inheritance diagram for QwtPlotCurve:

Public Types
enum	CurveStyle {   NoCurve = -1, Lines, Sticks, Steps,   Dots, UserCurve = 100 }
enum	CurveAttribute { Inverted = 0x01, Fitted = 0x02 }
enum	LegendAttribute { LegendNoAttribute = 0x00, LegendShowLine = 0x01, LegendShowSymbol = 0x02, LegendShowBrush = 0x04 }
enum	PaintAttribute { ClipPolygons = 0x01, FilterPoints = 0x02, MinimizeMemory = 0x04, ImageBuffer = 0x08 }
typedef QFlags< CurveAttribute >	CurveAttributes
	Curve attributes.
typedef QFlags< LegendAttribute >	LegendAttributes
	Legend attributes.
typedef QFlags< PaintAttribute >	PaintAttributes
	Paint attributes.
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_PlotSVG, Rtti_PlotTradingCurve,   Rtti_PlotBarChart, Rtti_PlotMultiBarChart, Rtti_PlotShape, Rtti_PlotTextLabel,   Rtti_PlotZone, 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. More...
enum	RenderHint { RenderAntialiased = 0x1 }
	Render hints. More...
typedef QFlags< ItemAttribute >	ItemAttributes
	Plot Item Attributes.
typedef QFlags< ItemInterest >	ItemInterests
	Plot Item Interests.
typedef QFlags< RenderHint >	RenderHints
	Render hints.

Public Member Functions
	QwtPlotCurve (const QString &title=QString())
	QwtPlotCurve (const QwtText &title)
virtual	~QwtPlotCurve ()
	Destructor.
virtual int	rtti () const
void	setPaintAttribute (PaintAttribute, bool on=true)
bool	testPaintAttribute (PaintAttribute) const
void	setLegendAttribute (LegendAttribute, bool on=true)
bool	testLegendAttribute (LegendAttribute) 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. More...
void	setSamples (const double *xData, const double *yData, int size)
void	setSamples (const QVector< double > &xData, const QVector< double > &yData)
	Initialize data with x- and y-arrays (explicitly shared) More...
void	setSamples (const QVector< QPointF > &)
void	setSamples (QwtSeriesData< QPointF > *)
int	closestPoint (const QPoint &pos, double *dist=NULL) const
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)
bool	testCurveAttribute (CurveAttribute) const
void	setPen (const QColor &, qreal width=0.0, Qt::PenStyle=Qt::SolidLine)
void	setPen (const QPen &)
const QPen &	pen () const
void	setBrush (const QBrush &)
	Assign a brush. More...
const QBrush &	brush () const
void	setBaseline (double)
	Set the value of the baseline. More...
double	baseline () const
void	setStyle (CurveStyle style)
CurveStyle	style () const
void	setSymbol (QwtSymbol *)
	Assign a symbol. More...
const QwtSymbol *	symbol () const
void	setCurveFitter (QwtCurveFitter *)
QwtCurveFitter *	curveFitter () const
virtual void	drawSeries (QPainter *, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect, int from, int to) const
virtual QwtGraphic	legendIcon (int index, const QSizeF &) const
Public Member Functions inherited from QwtPlotSeriesItem
	QwtPlotSeriesItem (const QString &title=QString())
	QwtPlotSeriesItem (const QwtText &title)
virtual	~QwtPlotSeriesItem ()
	Destructor.
void	setOrientation (Qt::Orientation)
Qt::Orientation	orientation () const
virtual void	draw (QPainter *, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &) const
	Draw the complete series. More...
virtual QRectF	boundingRect () const
virtual void	updateScaleDiv (const QwtScaleDiv &, const QwtScaleDiv &)
	Update the item to changes of the axes scale division. More...
Public Member Functions inherited from QwtPlotItem
	QwtPlotItem (const QwtText &title=QwtText())
virtual	~QwtPlotItem ()
	Destroy the QwtPlotItem.
void	attach (QwtPlot *plot)
	Attach the item to a plot. More...
void	detach ()
	This method detaches a QwtPlotItem from any QwtPlot it has been associated with. More...
QwtPlot *	plot () const
	Return attached plot.
void	setTitle (const QString &title)
void	setTitle (const QwtText &title)
const QwtText &	title () const
void	setItemAttribute (ItemAttribute, bool on=true)
bool	testItemAttribute (ItemAttribute) const
void	setItemInterest (ItemInterest, bool on=true)
bool	testItemInterest (ItemInterest) const
void	setRenderHint (RenderHint, bool on=true)
bool	testRenderHint (RenderHint) const
void	setRenderThreadCount (uint numThreads)
uint	renderThreadCount () const
void	setLegendIconSize (const QSize &)
QSize	legendIconSize () const
double	z () const
void	setZ (double z)
	Set the z value. More...
void	show ()
	Show the item.
void	hide ()
	Hide the item.
virtual void	setVisible (bool)
bool	isVisible () const
void	setAxes (int xAxis, int yAxis)
void	setXAxis (int axis)
int	xAxis () const
	Return xAxis.
void	setYAxis (int axis)
int	yAxis () const
	Return yAxis.
virtual void	itemChanged ()
virtual void	legendChanged ()
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. More...
virtual void	updateLegend (const QwtPlotItem *, const QList< QwtLegendData > &)
	Update the item to changes of the legend info. More...
QRectF	scaleRect (const QwtScaleMap &, const QwtScaleMap &) const
	Calculate the bounding scale rectangle of 2 maps. More...
QRectF	paintRect (const QwtScaleMap &, const QwtScaleMap &) const
	Calculate the bounding paint rectangle of 2 maps. More...
virtual QList< QwtLegendData >	legendData () const
	Return all information, that is needed to represent the item on the legend. More...
Public Member Functions inherited from QwtSeriesStore< QPointF >
	QwtSeriesStore ()
	Constructor The store contains no series.
	~QwtSeriesStore ()
	Destructor.
void	setData (QwtSeriesData< QPointF > *series)
QwtSeriesData< QPointF > *	data ()
const QwtSeriesData< QPointF > *	data () const
QPointF	sample (int index) const
virtual size_t	dataSize () const
virtual QRectF	dataRect () const
virtual void	setRectOfInterest (const QRectF &rect)
QwtSeriesData< QPointF > *	swapData (QwtSeriesData< QPointF > *series)

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. More...
virtual void	drawSymbols (QPainter *, const QwtSymbol &, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect, int from, int to) const
virtual void	drawLines (QPainter *, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect, int from, int to) const
	Draw lines. More...
virtual void	drawSticks (QPainter *, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect, int from, int to) const
virtual void	drawDots (QPainter *, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect, int from, int to) const
virtual void	drawSteps (QPainter *, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect, int from, int to) const
virtual void	fillCurve (QPainter *, const QwtScaleMap &, const QwtScaleMap &, const QRectF &canvasRect, QPolygonF &) const
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. More...
Protected Member Functions inherited from QwtPlotSeriesItem
virtual void	dataChanged ()
	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. More...
Protected Member Functions inherited from QwtAbstractSeriesStore
virtual	~QwtAbstractSeriesStore ()
	Destructor.
virtual QRectF	dataRect () const =0
virtual size_t	dataSize () const =0

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.

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 QPoint &	pos,
		double *	dist = NULL
	)		const

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()

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()

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()

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

setSamples() [1/4]

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() [2/4]

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() [3/4]

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() [4/4]

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()