QCPErrorBars Class Reference

A plottable that adds a set of error bars to other plottables. More...

Inheritance diagram for QCPErrorBars:

Public Types
enum	ErrorType { etKeyError , etValueError }

Public Member Functions
	QCPErrorBars (QCPAxis *keyAxis, QCPAxis *valueAxis)
QSharedPointer< QCPErrorBarsDataContainer >	data () const
QCPAbstractPlottable *	dataPlottable () const
ErrorType	errorType () const
double	whiskerWidth () const
double	symbolGap () const
void	setData (QSharedPointer< QCPErrorBarsDataContainer > data)
void	setData (const QVector< double > &error)
void	setData (const QVector< double > &errorMinus, const QVector< double > &errorPlus)
void	setDataPlottable (QCPAbstractPlottable *plottable)
void	setErrorType (ErrorType type)
void	setWhiskerWidth (double pixels)
void	setSymbolGap (double pixels)
void	addData (const QVector< double > &error)
void	addData (const QVector< double > &errorMinus, const QVector< double > &errorPlus)
void	addData (double error)
void	addData (double errorMinus, double errorPlus)
virtual int	dataCount () const Q_DECL_OVERRIDE
virtual double	dataMainKey (int index) const Q_DECL_OVERRIDE
virtual double	dataSortKey (int index) const Q_DECL_OVERRIDE
virtual double	dataMainValue (int index) const Q_DECL_OVERRIDE
virtual QCPRange	dataValueRange (int index) const Q_DECL_OVERRIDE
virtual QPointF	dataPixelPosition (int index) const Q_DECL_OVERRIDE
virtual bool	sortKeyIsMainKey () const Q_DECL_OVERRIDE
virtual QCPDataSelection	selectTestRect (const QRectF &rect, bool onlySelectable) const Q_DECL_OVERRIDE
virtual int	findBegin (double sortKey, bool expandedRange=true) const Q_DECL_OVERRIDE
virtual int	findEnd (double sortKey, bool expandedRange=true) const Q_DECL_OVERRIDE
virtual double	selectTest (const QPointF &pos, bool onlySelectable, QVariant *details=nullptr) const Q_DECL_OVERRIDE
virtual QCPPlottableInterface1D *	interface1D () Q_DECL_OVERRIDE
Public Member Functions inherited from QCPAbstractPlottable
	QCPAbstractPlottable (QCPAxis *keyAxis, QCPAxis *valueAxis)
QString	name () const
bool	antialiasedFill () const
bool	antialiasedScatters () const
QPen	pen () const
QBrush	brush () const
QCPAxis *	keyAxis () const
QCPAxis *	valueAxis () const
QCP::SelectionType	selectable () const
bool	selected () const
QCPDataSelection	selection () const
QCPSelectionDecorator *	selectionDecorator () const
void	setName (const QString &name)
void	setAntialiasedFill (bool enabled)
void	setAntialiasedScatters (bool enabled)
void	setPen (const QPen &pen)
void	setBrush (const QBrush &brush)
void	setKeyAxis (QCPAxis *axis)
void	setValueAxis (QCPAxis *axis)
Q_SLOT void	setSelectable (QCP::SelectionType selectable)
Q_SLOT void	setSelection (QCPDataSelection selection)
void	setSelectionDecorator (QCPSelectionDecorator *decorator)
void	coordsToPixels (double key, double value, double &x, double &y) const
const QPointF	coordsToPixels (double key, double value) const
void	pixelsToCoords (double x, double y, double &key, double &value) const
void	pixelsToCoords (const QPointF &pixelPos, double &key, double &value) const
void	rescaleAxes (bool onlyEnlarge=false) const
void	rescaleKeyAxis (bool onlyEnlarge=false) const
void	rescaleValueAxis (bool onlyEnlarge=false, bool inKeyRange=false) const
bool	addToLegend (QCPLegend *legend)
bool	addToLegend ()
bool	removeFromLegend (QCPLegend *legend) const
bool	removeFromLegend () const
Public Member Functions inherited from QCPLayerable
	QCPLayerable (QCustomPlot *plot, QString targetLayer=QString(), QCPLayerable *parentLayerable=nullptr)
bool	visible () const
QCustomPlot *	parentPlot () const
QCPLayerable *	parentLayerable () const
QCPLayer *	layer () const
bool	antialiased () const
void	setVisible (bool on)
Q_SLOT bool	setLayer (QCPLayer *layer)
bool	setLayer (const QString &layerName)
void	setAntialiased (bool enabled)
bool	realVisibility () const

Protected Member Functions
virtual void	draw (QCPPainter *painter) Q_DECL_OVERRIDE
virtual void	drawLegendIcon (QCPPainter *painter, const QRectF &rect) const Q_DECL_OVERRIDE
virtual QCPRange	getKeyRange (bool &foundRange, QCP::SignDomain inSignDomain=QCP::sdBoth) const Q_DECL_OVERRIDE
virtual QCPRange	getValueRange (bool &foundRange, QCP::SignDomain inSignDomain=QCP::sdBoth, const QCPRange &inKeyRange=QCPRange()) const Q_DECL_OVERRIDE
void	getErrorBarLines (QCPErrorBarsDataContainer::const_iterator it, QVector< QLineF > &backbones, QVector< QLineF > &whiskers) const
void	getVisibleDataBounds (QCPErrorBarsDataContainer::const_iterator &begin, QCPErrorBarsDataContainer::const_iterator &end, const QCPDataRange &rangeRestriction) const
double	pointDistance (const QPointF &pixelPoint, QCPErrorBarsDataContainer::const_iterator &closestData) const
void	getDataSegments (QList< QCPDataRange > &selectedSegments, QList< QCPDataRange > &unselectedSegments) const
bool	errorBarVisible (int index) const
bool	rectIntersectsLine (const QRectF &pixelRect, const QLineF &line) const
Protected Member Functions inherited from QCPAbstractPlottable
virtual QRect	clipRect () const Q_DECL_OVERRIDE
virtual QCP::Interaction	selectionCategory () const Q_DECL_OVERRIDE
void	applyDefaultAntialiasingHint (QCPPainter *painter) const Q_DECL_OVERRIDE
virtual void	selectEvent (QMouseEvent *event, bool additive, const QVariant &details, bool *selectionStateChanged) Q_DECL_OVERRIDE
virtual void	deselectEvent (bool *selectionStateChanged) Q_DECL_OVERRIDE
void	applyFillAntialiasingHint (QCPPainter *painter) const
void	applyScattersAntialiasingHint (QCPPainter *painter) const
Protected Member Functions inherited from QCPLayerable
virtual void	parentPlotInitialized (QCustomPlot *parentPlot)
virtual void	mousePressEvent (QMouseEvent *event, const QVariant &details)
virtual void	mouseMoveEvent (QMouseEvent *event, const QPointF &startPos)
virtual void	mouseReleaseEvent (QMouseEvent *event, const QPointF &startPos)
virtual void	mouseDoubleClickEvent (QMouseEvent *event, const QVariant &details)
virtual void	wheelEvent (QWheelEvent *event)
void	initializeParentPlot (QCustomPlot *parentPlot)
void	setParentLayerable (QCPLayerable *parentLayerable)
bool	moveToLayer (QCPLayer *layer, bool prepend)
void	applyAntialiasingHint (QCPPainter *painter, bool localAntialiased, QCP::AntialiasedElement overrideElement) const

Protected Attributes
QSharedPointer< QCPErrorBarsDataContainer >	mDataContainer
QPointer< QCPAbstractPlottable >	mDataPlottable
ErrorType	mErrorType
double	mWhiskerWidth
double	mSymbolGap
Protected Attributes inherited from QCPAbstractPlottable
QString	mName
bool	mAntialiasedFill
bool	mAntialiasedScatters
QPen	mPen
QBrush	mBrush
QPointer< QCPAxis >	mKeyAxis
QPointer< QCPAxis >	mValueAxis
QCP::SelectionType	mSelectable
QCPDataSelection	mSelection
QCPSelectionDecorator *	mSelectionDecorator
Protected Attributes inherited from QCPLayerable
bool	mVisible
QCustomPlot *	mParentPlot
QPointer< QCPLayerable >	mParentLayerable
QCPLayer *	mLayer
bool	mAntialiased

Friends
class	QCustomPlot
class	QCPLegend

Additional Inherited Members
Signals inherited from QCPAbstractPlottable
void	selectionChanged (bool selected)
void	selectionChanged (const QCPDataSelection &selection)
void	selectableChanged (QCP::SelectionType selectable)
Signals inherited from QCPLayerable
void	layerChanged (QCPLayer *newLayer)

Detailed Description

A plottable that adds a set of error bars to other plottables.

The QCPErrorBars plottable can be attached to other one-dimensional plottables (e.g. QCPGraph, QCPCurve, QCPBars, etc.) and equips them with error bars.

Use setDataPlottable to define for which plottable the QCPErrorBars shall display the error bars. The orientation of the error bars can be controlled with setErrorType.

By using setData, you can supply the actual error data, either as symmetric error or plus/minus asymmetric errors. QCPErrorBars only stores the error data. The absolute key/value position of each error bar will be adopted from the configured data plottable. The error data of the QCPErrorBars are associated one-to-one via their index to the data points of the data plottable. You can directly access and manipulate the error bar data via data.

Set either of the plus/minus errors to NaN (qQNaN() or std::numeric_limits<double>::quiet_NaN()) to not show the respective error bar on the data point at that index.

Changing the appearance

The appearance of the error bars is defined by the pen (setPen), and the width of the whiskers (setWhiskerWidth). Further, the error bar backbones may leave a gap around the data point center to prevent that error bars are drawn too close to or even through scatter points. This gap size can be controlled via setSymbolGap.

Member Enumeration Documentation

ErrorType

enum QCPErrorBars::ErrorType

Defines in which orientation the error bars shall appear. If your data needs both error dimensions, create two QCPErrorBars with different ErrorType.

See also

setErrorType

Enumerator
etKeyError	The errors are for the key dimension (bars appear parallel to the key axis)
etValueError	The errors are for the value dimension (bars appear parallel to the value axis)

Constructor & Destructor Documentation

QCPErrorBars()

QCPErrorBars::QCPErrorBars ( QCPAxis * keyAxis, QCPAxis * valueAxis )

explicit

Constructs an error bars plottable which uses keyAxis as its key axis ("x") and valueAxis as its value axis ("y"). keyAxis and valueAxis must reside in the same QCustomPlot instance and not have the same orientation. If either of these restrictions is violated, a corresponding message is printed to the debug output (qDebug), the construction is not aborted, though.

It is also important that the keyAxis and valueAxis are the same for the error bars plottable and the data plottable that the error bars shall be drawn on (setDataPlottable).

The created QCPErrorBars is automatically registered with the QCustomPlot instance inferred from keyAxis. This QCustomPlot instance takes ownership of the QCPErrorBars, so do not delete it manually but use QCustomPlot::removePlottable() instead.

Member Function Documentation

addData() [1/4]

void QCPErrorBars::addData

(

const QVector< double > &

error

)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Adds symmetrical error values as specified in error. The errors will be associated one-to-one by the data point index to the associated data plottable (setDataPlottable).

You can directly access and manipulate the error bar data via data.

See also

setData

addData() [2/4]

void QCPErrorBars::addData	(	const QVector< double > &	errorMinus,
		const QVector< double > &	errorPlus )

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Adds asymmetrical errors as specified in errorMinus and errorPlus. The errors will be associated one-to-one by the data point index to the associated data plottable (setDataPlottable).

You can directly access and manipulate the error bar data via data.

See also

setData

addData() [3/4]

void QCPErrorBars::addData

(

double

error

)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Adds a single symmetrical error bar as specified in error. The errors will be associated one-to-one by the data point index to the associated data plottable (setDataPlottable).

You can directly access and manipulate the error bar data via data.

See also

setData

addData() [4/4]

void QCPErrorBars::addData	(	double	errorMinus,
		double	errorPlus )

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Adds a single asymmetrical error bar as specified in errorMinus and errorPlus. The errors will be associated one-to-one by the data point index to the associated data plottable (setDataPlottable).

You can directly access and manipulate the error bar data via data.

See also

setData

data()

QSharedPointer< QCPErrorBarsDataContainer > QCPErrorBars::data ( ) const

inline

Returns a shared pointer to the internal data storage of type QCPErrorBarsDataContainer. You may use it to directly manipulate the error values, which may be more convenient and faster than using the regular setData methods.

dataCount()

int QCPErrorBars::dataCount ( ) const

virtual

Returns the number of data points of the plottable.

Implements QCPPlottableInterface1D.

dataMainKey()

double QCPErrorBars::dataMainKey ( int index ) const

virtual

Returns the main key of the data point at the given index.

What the main key is, is defined by the plottable's data type. See the QCPDataContainer DataType documentation for details about this naming convention.

Implements QCPPlottableInterface1D.

dataMainValue()

double QCPErrorBars::dataMainValue ( int index ) const

virtual

Returns the main value of the data point at the given index.

What the main value is, is defined by the plottable's data type. See the QCPDataContainer DataType documentation for details about this naming convention.

Implements QCPPlottableInterface1D.

dataPixelPosition()

QPointF QCPErrorBars::dataPixelPosition ( int index ) const

virtual

Returns the pixel position on the widget surface at which the data point at the given index appears.

Usually this corresponds to the point of dataMainKey/ dataMainValue, in pixel coordinates. However, depending on the plottable, this might be a different apparent position than just a coord-to-pixel transform of those values. For example, QCPBars apparent data values can be shifted depending on their stacking, bar grouping or configured base value.

Implements QCPPlottableInterface1D.

dataSortKey()

double QCPErrorBars::dataSortKey ( int index ) const

virtual

Returns the sort key of the data point at the given index.

What the sort key is, is defined by the plottable's data type. See the QCPDataContainer DataType documentation for details about this naming convention.

Implements QCPPlottableInterface1D.

dataValueRange()

QCPRange QCPErrorBars::dataValueRange ( int index ) const

virtual

Returns the value range of the data point at the given index.

What the value range is, is defined by the plottable's data type. See the QCPDataContainer DataType documentation for details about this naming convention.

Implements QCPPlottableInterface1D.

draw()

void QCPErrorBars::draw ( QCPPainter * painter )

protectedvirtual

Implements QCPAbstractPlottable.

drawLegendIcon()

void QCPErrorBars::drawLegendIcon ( QCPPainter * painter, const QRectF & rect ) const

protectedvirtual

Implements QCPAbstractPlottable.

findBegin()

int QCPErrorBars::findBegin ( double sortKey, bool expandedRange = true ) const

virtual

Returns the index of the data point with a (sort-)key that is equal to, just below, or just above sortKey. If expandedRange is true, the data point just below sortKey will be considered, otherwise the one just above.

This can be used in conjunction with findEnd to iterate over data points within a given key range, including or excluding the bounding data points that are just beyond the specified range.

If expandedRange is true but there are no data points below sortKey, 0 is returned.

If the container is empty, returns 0 (in that case, findEnd will also return 0, so a loop using these methods will not iterate over the index 0).

See also

findEnd, QCPDataContainer::findBegin

Implements QCPPlottableInterface1D.

findEnd()

int QCPErrorBars::findEnd ( double sortKey, bool expandedRange = true ) const

virtual

Returns the index one after the data point with a (sort-)key that is equal to, just above, or just below sortKey. If expandedRange is true, the data point just above sortKey will be considered, otherwise the one just below.

This can be used in conjunction with findBegin to iterate over data points within a given key range, including the bounding data points that are just below and above the specified range.

If expandedRange is true but there are no data points above sortKey, the index just above the highest data point is returned.

If the container is empty, returns 0.

See also

findBegin, QCPDataContainer::findEnd

Implements QCPPlottableInterface1D.

getKeyRange()

QCPRange QCPErrorBars::getKeyRange ( bool & foundRange, QCP::SignDomain inSignDomain = QCP::sdBoth ) const

protectedvirtual

Returns the coordinate range that all data in this plottable span in the key axis dimension. For logarithmic plots, one can set inSignDomain to either QCP::sdNegative or QCP::sdPositive in order to restrict the returned range to that sign domain. E.g. when only negative range is wanted, set inSignDomain to QCP::sdNegative and all positive points will be ignored for range calculation. For no restriction, just set inSignDomain to QCP::sdBoth (default). foundRange is an output parameter that indicates whether a range could be found or not. If this is false, you shouldn't use the returned range (e.g. no points in data).

Note that foundRange is not the same as QCPRange::validRange, since the range returned by this function may have size zero (e.g. when there is only one data point). In this case foundRange would return true, but the returned range is not a valid range in terms of QCPRange::validRange.

See also

rescaleAxes, getValueRange

Implements QCPAbstractPlottable.

getValueRange()

QCPRange QCPErrorBars::getValueRange ( bool & foundRange, QCP::SignDomain inSignDomain = QCP::sdBoth, const QCPRange & inKeyRange = QCPRange() ) const

protectedvirtual

Returns the coordinate range that the data points in the specified key range (inKeyRange) span in the value axis dimension. For logarithmic plots, one can set inSignDomain to either QCP::sdNegative or QCP::sdPositive in order to restrict the returned range to that sign domain. E.g. when only negative range is wanted, set inSignDomain to QCP::sdNegative and all positive points will be ignored for range calculation. For no restriction, just set inSignDomain to QCP::sdBoth (default). foundRange is an output parameter that indicates whether a range could be found or not. If this is false, you shouldn't use the returned range (e.g. no points in data).

If inKeyRange has both lower and upper bound set to zero (is equal to QCPRange()), all data points are considered, without any restriction on the keys.

Note that foundRange is not the same as QCPRange::validRange, since the range returned by this function may have size zero (e.g. when there is only one data point). In this case foundRange would return true, but the returned range is not a valid range in terms of QCPRange::validRange.

See also

rescaleAxes, getKeyRange

Implements QCPAbstractPlottable.

interface1D()

virtual QCPPlottableInterface1D * QCPErrorBars::interface1D ( )

inlinevirtual

If this plottable is a one-dimensional plottable, i.e. it implements the QCPPlottableInterface1D, returns the this pointer with that type. Otherwise (e.g. in the case of a QCPColorMap) returns zero.

You can use this method to gain read access to data coordinates while holding a pointer to the abstract base class only.

Reimplemented from QCPAbstractPlottable.

selectTest()

double QCPErrorBars::selectTest ( const QPointF & pos, bool onlySelectable, QVariant * details = nullptr ) const

virtual

Implements a selectTest specific to this plottable's point geometry.

If details is not 0, it will be set to a QCPDataSelection, describing the closest data point to pos.

\seebaseclassmethod QCPAbstractPlottable::selectTest

Implements QCPAbstractPlottable.

selectTestRect()

QCPDataSelection QCPErrorBars::selectTestRect ( const QRectF & rect, bool onlySelectable ) const

virtual

Returns a data selection containing all the data points of this plottable which are contained (or hit by) rect. This is used mainly in the selection rect interaction for data selection (data selection mechanism).

If onlySelectable is true, an empty QCPDataSelection is returned if this plottable is not selectable (i.e. if QCPAbstractPlottable::setSelectable is QCP::stNone).

Note

rect must be a normalized rect (positive or zero width and height). This is especially important when using the rect of QCPSelectionRect::accepted, which is not necessarily normalized. Use QRect::normalized() when passing a rect which might not be normalized.

Implements QCPPlottableInterface1D.

setData() [1/3]

void QCPErrorBars::setData

(

const QVector< double > &

error

)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Sets symmetrical error values as specified in error. The errors will be associated one-to-one by the data point index to the associated data plottable (setDataPlottable).

You can directly access and manipulate the error bar data via data.

See also

addData

setData() [2/3]

void QCPErrorBars::setData	(	const QVector< double > &	errorMinus,
		const QVector< double > &	errorPlus )

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Sets asymmetrical errors as specified in errorMinus and errorPlus. The errors will be associated one-to-one by the data point index to the associated data plottable (setDataPlottable).

You can directly access and manipulate the error bar data via data.

See also

addData

setData() [3/3]

void QCPErrorBars::setData

(

QSharedPointer< QCPErrorBarsDataContainer >

data

)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Replaces the current data container with the provided data container.

Since a QSharedPointer is used, multiple QCPErrorBars instances may share the same data container safely. Modifying the data in the container will then affect all QCPErrorBars instances that share the container. Sharing can be achieved by simply exchanging the data containers wrapped in shared pointers:

If you do not wish to share containers, but create a copy from an existing container, assign the data containers directly:

(This uses different notation compared with other plottables, because the QCPErrorBars uses a QVector<QCPErrorBarsData> as its data container, instead of a QCPDataContainer.)

See also

addData

setDataPlottable()

void QCPErrorBars::setDataPlottable

(

QCPAbstractPlottable *

plottable

)

Sets the data plottable to which the error bars will be applied. The error values specified e.g. via setData will be associated one-to-one by the data point index to the data points of plottable. This means that the error bars will adopt the key/value coordinates of the data point with the same index.

The passed plottable must be a one-dimensional plottable, i.e. it must implement the QCPPlottableInterface1D. Further, it must not be a QCPErrorBars instance itself. If either of these restrictions is violated, a corresponding qDebug output is generated, and the data plottable of this QCPErrorBars instance is set to zero.

For proper display, care must also be taken that the key and value axes of the plottable match those configured for this QCPErrorBars instance.

setErrorType()

void QCPErrorBars::setErrorType

(

ErrorType

type

)

Sets in which orientation the error bars shall appear on the data points. If your data needs both error dimensions, create two QCPErrorBars with different type.

setSymbolGap()

void QCPErrorBars::setSymbolGap

(

double

pixels

)

Sets the gap diameter around the data points that will be left out when drawing the error bar backbones. This gap prevents that error bars are drawn too close to or even through scatter points.

setWhiskerWidth()

void QCPErrorBars::setWhiskerWidth

(

double

pixels

)

Sets the width of the whiskers (the short bars at the end of the actual error bar backbones) to pixels.

sortKeyIsMainKey()

bool QCPErrorBars::sortKeyIsMainKey ( ) const

virtual

Returns whether the sort key (dataSortKey) is identical to the main key (dataMainKey).

What the sort and main keys are, is defined by the plottable's data type. See the QCPDataContainer DataType documentation for details about this naming convention.

Implements QCPPlottableInterface1D.

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

• qcustomplot.h
• qcustomplot.cpp