QwtPlotVectorField(3)

📦
version 6.3.0 · 2 versions
, in alpine 3.24

💖 NAME 💖

okay bestie, welcome to the QwtPlotVectorField(3) page from the Library Functions Manual — this is the plot-item-that-represents-a-vector-field situation, and it's lowkey iconic. QwtPlotVectorField — A plot item, that represents a vector field. Periodt. 💅

✨ SYNOPSIS ✨

#include <qwt_plot_vectorfield.h>

Inherits QwtPlotSeriesItem, and QwtSeriesStore< QwtVectorFieldSample >.

🎀 Public Types 🎀

  • enum IndicatorOrigin { OriginHead, OriginTail, OriginCenter }
  • enum PaintAttribute { FilterVectors = 0x01 }
  • enum MagnitudeMode { MagnitudeAsColor = 0x01, MagnitudeAsLength = 0x02 }
  • typedef QFlags< PaintAttribute > PaintAttributes
  • typedef QFlags< MagnitudeMode > MagnitudeModes

💅 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.
  • enum ItemAttribute { Legend = 0x01, AutoScale = 0x02, Margins = 0x04 } — Plot Item Attributes.
  • enum ItemInterest { ScaleInterest = 0x01, LegendInterest = 0x02 } — Plot Item Interests.
  • enum RenderHint { RenderAntialiased = 0x1 } — Render hints.
  • typedef QFlags< ItemAttribute > ItemAttributes
  • typedef QFlags< ItemInterest > ItemInterests
  • typedef QFlags< RenderHint > RenderHints

🌸 Public Member Functions 🌸

  • QwtPlotVectorField (const QString &title=QString())
  • QwtPlotVectorField (const QwtText &title)
  • virtual ~QwtPlotVectorField () — Destructor.
  • void setPaintAttribute (PaintAttribute, bool on=true)
  • bool testPaintAttribute (PaintAttribute) const
  • void setMagnitudeMode (MagnitudeMode, bool on=true)
  • bool testMagnitudeMode (MagnitudeMode) const
  • void setSymbol (QwtVectorFieldSymbol *)
  • const QwtVectorFieldSymbol * symbol () const
  • void setPen (const QPen &)
  • QPen pen () const
  • void setBrush (const QBrush &) — Assign a brush.
  • QBrush brush () const
  • void setRasterSize (const QSizeF &)
  • QSizeF rasterSize () const
  • void setIndicatorOrigin (IndicatorOrigin)
  • IndicatorOrigin indicatorOrigin () const
  • void setSamples (const QVector< QwtVectorFieldSample > &)
  • void setSamples (QwtVectorFieldData *)
  • void setColorMap (QwtColorMap *)
  • const QwtColorMap * colorMap () const
  • void setMagnitudeRange (const QwtInterval &)
  • QwtInterval magnitudeRange () const
  • void setMinArrowLength (double)
  • double minArrowLength () const
  • void setMaxArrowLength (double)
  • double maxArrowLength () const
  • virtual double arrowLength (double magnitude) const
  • virtual QRectF boundingRect () const override
  • virtual void drawSeries (QPainter *, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect, int from, int to) const override
  • virtual int rtti () const override
  • virtual QwtGraphic legendIcon (int index, const QSizeF &) const override
  • void setMagnitudeScaleFactor (double factor) — Set the magnitudeScaleFactor.
  • double magnitudeScaleFactor () 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 &canvasRect) const override — Draw the complete series.
  • virtual void updateScaleDiv (const QwtScaleDiv &, const QwtScaleDiv &) override — Update the item to changes of the axes scale division.

🌈 Public Member Functions inherited from QwtPlotItem 🌈

  • QwtPlotItem ()
  • QwtPlotItem (const QString &title)
  • QwtPlotItem (const QwtText &title)
  • 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)
  • 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.
  • void show () — Show the item.
  • void hide () — Hide the item.
  • virtual void setVisible (bool)
  • bool isVisible () const
  • void setAxes (QwtAxisId xAxis, QwtAxisId yAxis)
  • void setXAxis (QwtAxisId)
  • QwtAxisId xAxis () const — Return xAxis.
  • void setYAxis (QwtAxisId)
  • QwtAxisId 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.
  • 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< QwtVectorFieldSample > 💜

  • QwtSeriesStore () — Constructor. The store contains no series.
  • ~QwtSeriesStore () — Destructor.
  • void setData (QwtSeriesData< QwtVectorFieldSample > *series)
  • QwtSeriesData< QwtVectorFieldSample > * data ()
  • QwtVectorFieldSample sample (int index) const
  • virtual size_t dataSize () const override
  • virtual QRectF dataRect () const override
  • virtual void setRectOfInterest (const QRectF &rect) override
  • QwtSeriesData< QwtVectorFieldSample > * swapData (QwtSeriesData< QwtVectorFieldSample > *series)

🎀 Protected Member Functions 🎀

  • virtual void drawSymbols (QPainter *, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect, int from, int to) const
  • virtual void drawSymbol (QPainter *, double x, double y, double vx, double vy) const
  • virtual void dataChanged () 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 vector field.

A vector field is a representation of a points with a given magnitude and direction as arrows. While the direction affects the direction of the arrow, the magnitude might be represented as a color or by the length of the arrow.

See also: QwtVectorFieldSymbol, QwtVectorFieldSample

Definition at line 30 of file qwt_plot_vectorfield.h.

🦋 Member Typedef Documentation 🦋

  • typedef QFlags<MagnitudeMode > QwtPlotVectorField::MagnitudeModes — An ORed combination of MagnitudeMode values.

Definition at line 90 of file qwt_plot_vectorfield.h.

  • typedef QFlags<PaintAttribute > QwtPlotVectorField::PaintAttributes — An ORed combination of PaintAttribute values.

Definition at line 67 of file qwt_plot_vectorfield.h.

💀 Member Enumeration Documentation 💀

  • enum QwtPlotVectorField::IndicatorOrigin — Depending on the origin the indicator symbol ( usually an arrow ) will be to the position of the corresponding sample.
    • OriginHead — symbol points to the sample position
    • OriginTail — The arrow starts at the sample position.
    • OriginCenter — The arrow is centered at the sample position.

Definition at line 39 of file qwt_plot_vectorfield.h.

  • enum QwtPlotVectorField::MagnitudeMode — Depending on the MagnitudeMode the magnitude component will have an impact on the attributes of the symbol/arrow.

See also: setMagnitudeMode()

  • MagnitudeAsColor — The magnitude will be mapped to a color using a color map

See also: magnitudeRange(), colorMap()

  • MagnitudeAsLength — The magnitude will have an impact on the length of the arrow/symbol

See also: arrowLength(), magnitudeScaleFactor()

Definition at line 75 of file qwt_plot_vectorfield.h.

  • enum QwtPlotVectorField::PaintAttribute — Attributes to modify the rendering

See also: setPaintAttribute(), testPaintAttribute()

Value from the synopsis, bestie: FilterVectors = 0x01.

Definition at line 55 of file qwt_plot_vectorfield.h.

🌈 Constructor & Destructor Documentation 🌈

  • QwtPlotVectorField::QwtPlotVectorField (const QString & title = QString()) [explicit] — Constructor

Parameters:

  • title — Title of the curve

Definition at line 302 of file qwt_plot_vectorfield.cpp.

  • QwtPlotVectorField::QwtPlotVectorField (const QwtText & title) [explicit] — Constructor

Parameters:

  • title — Title of the curve

Definition at line 292 of file qwt_plot_vectorfield.cpp.

  • QwtPlotVectorField::~QwtPlotVectorField () [virtual] — Destructor.

Definition at line 309 of file qwt_plot_vectorfield.cpp.

💅 Member Function Documentation 💅

  • double QwtPlotVectorField::arrowLength (double magnitude) const [virtual] — Computes length of the arrow in screen coordinate units based on its magnitude.

Default implementation simply scales the vector using the magnitudeScaleFactor() If the result is not null, the length is then bounded into the interval [ minArrowLength(), maxArrowLength() ].

Re-implement this function to provide special handling for zero/non-zero magnitude arrows, or impose minimum/maximum arrow length limits.

Parameters:

  • magnitude — Magnitude

Returns: Length of arrow to be drawn in dependence of vector magnitude.

See also: magnitudeScaleFactor, minArrowLength(), maxArrowLength()

Note: Has no effect when QwtPlotVectorField::MagnitudeAsLength is not enabled

Definition at line 726 of file qwt_plot_vectorfield.cpp.

  • QRectF QwtPlotVectorField::boundingRect () const [override], [virtual]

Returns: An invalid bounding rect: QRectF(1.0, 1.0, -2.0, -2.0)

Note — a width or height < 0.0 is ignored by the autoscaler, no cap. So don't come crying if your negative size does nothing, bestie 💅

Reimplemented from QwtPlotSeriesItem.

Definition at line 749 of file qwt_plot_vectorfield.cpp.

QBrush QwtPlotVectorField::brush () const

Returns the brush that fills the symbol 🎨

See also: setBrush(), pen()

Definition at line 379 of file qwt_plot_vectorfield.cpp.

const QwtColorMap * QwtPlotVectorField::colorMap () const

Hands you back the Color Map used for mapping intensity values into colors 🌈 the whole glow-up of your field, honestly.

See also: setColorMap()

Definition at line 590 of file qwt_plot_vectorfield.cpp.

void QwtPlotVectorField::dataChanged () [override] [protected] [virtual]

Okay so dataChanged() is literally the "hey bestie something changed" signal — it indicates that the series has been changed. ✨

Reimplemented from QwtPlotSeriesItem.

Definition at line 1034 of file qwt_plot_vectorfield.cpp.

void QwtPlotVectorField::drawSeries (...) [override] [virtual]

Draw a subset of the points 🖌️ the main character of this whole class, ngl.

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

Parameters:

  • painter — the Painter, doing the actual drawing 🎀
  • 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 sample to be painted
  • to — Index of the last sample to be painted. If to < 0 the series will be painted to its last sample.

Implements QwtPlotSeriesItem.

Definition at line 807 of file qwt_plot_vectorfield.cpp.

void QwtPlotVectorField::drawSymbol (...) [protected] [virtual]

Draws an arrow/symbol at one specific position 🎯

void QwtPlotVectorField::drawSymbol (QPainter * painter, double x, double y,
    double vx, double vy) const

Heads up: x, y, are paint device coordinates, while vx, vy are from the corresponding sample. Two different coordinate universes, don't mix them up fr 😭

See also: setSymbol(), drawSeries()

Definition at line 975 of file qwt_plot_vectorfield.cpp.

void QwtPlotVectorField::drawSymbols (...) [protected] [virtual]

Draw symbols — plural, the whole squad 🫶

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

Parameters:

  • painter — Painter
  • xMap — x map
  • yMap — y map
  • canvasRect — Contents rectangle of the canvas
  • from — Index of the first sample to be painted
  • to — Index of the last sample to be painted

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

Definition at line 847 of file qwt_plot_vectorfield.cpp.

QwtPlotVectorField::IndicatorOrigin QwtPlotVectorField::indicatorOrigin () const

Returns the origin for the symbols/arrows 📍 like, where does the arrow start from, the whole vibe check of direction.

Definition at line 401 of file qwt_plot_vectorfield.cpp.

QwtGraphic QwtPlotVectorField::legendIcon (...) const [override] [virtual]

Returns the icon representing the vector fields on the legend 🖼️ the little glow-up in the legend box.

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

Parameters:

  • index — Index of the legend entry ( ignored as there is only one ) — yeah, only one entry, so index is just sitting there like 💀
  • size — Icon size

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

Reimplemented from QwtPlotItem.

Definition at line 770 of file qwt_plot_vectorfield.cpp.

QwtInterval QwtPlotVectorField::magnitudeRange () const

Returns the min/max magnitudes to be used for color map lookups 🎨 literally the range that gets fed into the color map.

See also: setMagnitudeRange(), colorMap()

Definition at line 645 of file qwt_plot_vectorfield.cpp.

double QwtPlotVectorField::magnitudeScaleFactor () const

Returns the Scale factor used to calculate the arrow length from the magnitude 📏

The length of the arrow in screen coordinate units is calculated by scaling the magnitude by the magnitudeScaleFactor.

Default implementation simply scales the vector using the magnitudeScaleFactor property. Re-implement this function to provide special handling for zero/non-zero magnitude arrows, or impose minimum/maximum arrow length limits. So go off, override it 👑

Returns: Length of arrow to be drawn in dependence of vector magnitude.

See also: magnitudeScaleFactor

Note: Has no effect when QwtPlotVectorField::MagnitudeAsLength is not enabled 🚨 so flip that mode on first or this does absolutely nothing.

Definition at line 440 of file qwt_plot_vectorfield.cpp.

double QwtPlotVectorField::maxArrowLength () const

Returns the maximum for the arrow length 📐 the ceiling, the limit, the "no bigger than this" energy.

See also: setMinArrowLength(), maxArrowLength(), arrowLength()

Note: Has no effect when QwtPlotVectorField::MagnitudeAsLength is not enabled 🚨

Definition at line 705 of file qwt_plot_vectorfield.cpp.

double QwtPlotVectorField::minArrowLength () const

Returns the minimum for the arrow length of non zero vectors 🐜✨ tiny but mighty.

See also: setMinArrowLength(), maxArrowLength(), arrowLength()

Note: Has no effect when QwtPlotVectorField::MagnitudeAsLength is not enabled 🚨

Definition at line 675 of file qwt_plot_vectorfield.cpp.

QPen QwtPlotVectorField::pen () const

Returns the Pen used to draw the lines ✒️

See also: setPen(), brush()

Definition at line 351 of file qwt_plot_vectorfield.cpp.

QSizeF QwtPlotVectorField::rasterSize () const

Returns the raster size used for filtering samples 🔲

See also: setRasterSize(), QwtPlotVectorField::FilterVectors

Definition at line 463 of file qwt_plot_vectorfield.cpp.

int QwtPlotVectorField::rtti () const [override] [virtual]

Returns QwtPlotItem::Rtti_PlotField 🏷️ that's the whole function, it just says who it is. iconic honestly.

Reimplemented from QwtPlotItem.

Definition at line 503 of file qwt_plot_vectorfield.cpp.

void QwtPlotVectorField::setBrush (const QBrush & brush)

Assign a brush 🖌️

Parameters:

  • brush — New brush

See also: brush(), pen()

Note: the brush is ignored in MagnitudeAsColor mode 🙈 so don't wonder why your cute brush vanished.

Definition at line 364 of file qwt_plot_vectorfield.cpp.

void QwtPlotVectorField::setColorMap (QwtColorMap * colorMap)

Change the color map 🎨✨

The color map is used to map the magnitude of a sample into a color using a known range for the magnitudes.

Parameters:

  • colorMap — Color Map

See also: colorMap(), magnitudeRange()

Definition at line 571 of file qwt_plot_vectorfield.cpp.

void QwtPlotVectorField::setIndicatorOrigin (IndicatorOrigin origin)

Set the origin for the symbols/arrows 📍

Parameters:

  • origin — Origin

See also: indicatorOrigin()

Definition at line 390 of file qwt_plot_vectorfield.cpp.

void QwtPlotVectorField::setMagnitudeMode (MagnitudeMode mode, bool on = true)

Specify a mode how to represent the magnitude an arrow/symbol 🧭 (yes the original says "a n arrow/symbol", we're keeping that typo real and untouched, periodt 💅)

Parameters:

  • mode — Mode
  • on — On/Off

See also: testMagnitudeMode()

Definition at line 602 of file qwt_plot_vectorfield.cpp.

void QwtPlotVectorField::setMagnitudeRange (const QwtInterval & magnitudeRange)

Sets the min/max magnitudes to be used for color map lookups 🎯

If invalid (min=max=0 or negative values), the range is determined from the current range of magnitudes in the vector samples. So it ✨auto-magically✨ figures itself out.

See also: magnitudeRange(), colorMap()

Definition at line 632 of file qwt_plot_vectorfield.cpp.

void QwtPlotVectorField::setMagnitudeScaleFactor (double factor)

Set the magnitudeScaleFactor. The length of the arrow in screen coordinate units is calculated by scaling the magnitude by the magnitudeScaleFactor. 📏💫

Parameters:

  • factor — Scale factor

See also: magnitudeScaleFactor(), arrowLength()

Note: Has no effect when QwtPlotVectorField::MagnitudeAsLength is not enabled 🚨

Definition at line 417 of file qwt_plot_vectorfield.cpp.

void QwtPlotVectorField::setMaxArrowLength (double length)

Set a maximum for the arrow length 📐

Parameters:

  • length — Maximum for the arrow length in pixels

See also: maxArrowLength(), setMinArrowLength(), arrowLength()

Note: Has no effect when QwtPlotVectorField::MagnitudeAsLength is not enabled 🚨

Definition at line 688 of file qwt_plot_vectorfield.cpp.

void QwtPlotVectorField::setMinArrowLength (double length)

Set a minimum for the arrow length of non zero vectors 🐜

Parameters:

  • length — Minimum for the arrow length in pixels

See also: minArrowLength(), setMaxArrowLength(), arrowLength()

Note: Has no effect when QwtPlotVectorField::MagnitudeAsLength is not enabled 🚨

Definition at line 658 of file qwt_plot_vectorfield.cpp.

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

Specify an attribute how to draw the curve 🎛️

Parameters:

  • attribute — Paint attribute
  • on — On/Off

See also: testPaintAttribute()

Definition at line 475 of file qwt_plot_vectorfield.cpp.

void QwtPlotVectorField::setPen (const QPen & pen)

Assign a pen ✒️

Parameters:

  • pen — New pen

See also: pen(), brush()

Note: the pen is ignored in MagnitudeAsColor mode 🙈 same deal as the brush.

Definition at line 336 of file qwt_plot_vectorfield.cpp.

void QwtPlotVectorField::setRasterSize (const QSizeF & size)

Set the raster size used for filtering samples 🔲

See also: rasterSize(), QwtPlotVectorField::FilterVectors

Definition at line 450 of file qwt_plot_vectorfield.cpp.

void QwtPlotVectorField::setSamples (const QVector< QwtVectorFieldSample > & samples)

Initialize data with an array of samples 📦✨

Parameters:

  • samples — Vector of points

Definition at line 541 of file qwt_plot_vectorfield.cpp.

void QwtPlotVectorField::setSamples (QwtVectorFieldData * data)

Assign a series of samples 📊

setSamples() is just a wrapper for setData() without any additional value - beside that it is easier to find for the developer. (real "we made it findable" energy, love that for us 🫶)

Parameters:

  • data — Data
Warning: The item takes ownership of the data object, deleting it when its not used anymore. 💀 So do not delete it yourself afterwards, bestie — double free is not the slay you think it is.

Definition at line 556 of file qwt_plot_vectorfield.cpp.

void QwtPlotVectorField::setSymbol (QwtVectorFieldSymbol * symbol)

Sets a new arrow symbol (implementation of arrow drawing code) 🏹✨

Parameters:

  • symbol — Arrow symbol

See also: symbol(), drawSymbol()

Note: Ownership is transferred to QwtPlotVectorField. 👑 you hand it over, it's theirs now.

Definition at line 516 of file qwt_plot_vectorfield.cpp.

const QwtVectorFieldSymbol * QwtPlotVectorField::symbol () const

Returns the arrow symbol 🏹

See also: setSymbol(), drawSymbol()

Definition at line 532 of file qwt_plot_vectorfield.cpp.

bool QwtPlotVectorField::testMagnitudeMode (MagnitudeMode mode) const

Returns True, when mode is enabled ✅

See also: MagnitudeMode, setMagnitudeMode()

Definition at line 619 of file qwt_plot_vectorfield.cpp.

bool QwtPlotVectorField::testPaintAttribute (PaintAttribute attribute) const

Returns True, when attribute is enabled ✅

See also: PaintAttribute, setPaintAttribute()

Definition at line 496 of file qwt_plot_vectorfield.cpp.

🫶 AUTHOR 🫶

okay so this page wasn't hand-written by some mysterious maintainer bestie — it was generated automatically by Doxygen for Qwt User's Guide from the source code. literally the docs built themselves from the code, no cap. so if something reads a little stiff, blame the generator, not a person 💅

and that's the whole page, bestie — you made it to the end 🎀✨ iconic behavior. this little beauty of a manual page comes to you courtesy of Qwt User's Guide, spun up by Doxygen straight from the source code, and it's filed under QwtPlotVectorField(3) 💖 go forth and draw some vector fields, you absolute main character 🦋👑

📦 where this page comes from