QwtPolarSpectrogram(3) Qwt User's Guide QwtPolarSpectrogram(3) NAME QwtPolarSpectrogram - An item, which displays a spectrogram. SYNOPSIS #include Inherits QwtPolarItem. Public Types enum PaintAttribute { ApproximatedAtan = 0x01 } typedef QFlags< PaintAttribute > PaintAttributes Public Member Functions QwtPolarSpectrogram () Constructor. virtual ~QwtPolarSpectrogram () Destructor. void setData (QwtRasterData *data) const QwtRasterData * data () const void setColorMap (QwtColorMap *) const QwtColorMap * colorMap () const void setPaintAttribute (PaintAttribute, bool on=true) bool testPaintAttribute (PaintAttribute) const virtual int rtti () const override virtual void draw (QPainter *painter, const QwtScaleMap &azimuthMap, const QwtScaleMap &radialMap, const QPointF &pole, double radius, const QRectF &canvasRect) const override virtual QwtInterval boundingInterval (int scaleId) const override Protected Member Functions virtual QImage renderImage (const QwtScaleMap &azimuthMap, const QwtScaleMap &radialMap, const QPointF &pole, const QRect &rect) const Render an image from the data and color map. virtual void renderTile (const QwtScaleMap &azimuthMap, const QwtScaleMap &radialMap, const QPointF &pole, const QPoint &imagePos, const QRect &tile, QImage *image) const Render a sub-rectangle of an image. Detailed Description An item, which displays a spectrogram. A spectrogram displays 3-dimensional data, where the 3rd dimension ( the intensity ) is displayed using colors. The colors are calculated from the values using a color map. See also QwtRasterData, QwtColorMap Definition at line 28 of file qwt_polar_spectrogram.h. Member Typedef Documentation typedef QFlags QwtPolarSpectrogram::PaintAttributes An ORed combination of PaintAttribute values. Definition at line 47 of file qwt_polar_spectrogram.h. Member Enumeration Documentation enum QwtPolarSpectrogram::PaintAttribute Attributes to modify the drawing algorithm. The default setting disables ApproximatedAtan See also setPaintAttribute(), testPaintAttribute() Enumerator ApproximatedAtan Use qwtFastAtan2 instead of atan2 for translating widget into polar coordinates. Definition at line 37 of file qwt_polar_spectrogram.h. Member Function Documentation QwtInterval QwtPolarSpectrogram::boundingInterval (int scaleId) const [override], [virtual] Interval, that is necessary to display the item This interval can be useful for operations like clipping or autoscaling Parameters scaleId Scale index Returns bounding interval ( == position ) See also position() Reimplemented from QwtPolarItem. Definition at line 443 of file qwt_polar_spectrogram.cpp. const QwtColorMap * QwtPolarSpectrogram::colorMap () const Returns Color Map used for mapping the intensity values to colors See also setColorMap() Definition at line 137 of file qwt_polar_spectrogram.cpp. const QwtRasterData * QwtPolarSpectrogram::data () const Returns Spectrogram data See also setData() Definition at line 106 of file qwt_polar_spectrogram.cpp. void QwtPolarSpectrogram::draw (QPainter * painter, const QwtScaleMap & azimuthMap, const QwtScaleMap & radialMap, const QPointF & pole, double radius, const QRectF & canvasRect) const [override], [virtual] Draw the spectrogram Parameters painter Painter azimuthMap Maps azimuth values to values related to 0.0, M_2PI radialMap Maps radius values into painter coordinates. pole Position of the pole in painter coordinates radius Radius of the complete plot area in painter coordinates canvasRect Contents rect of the canvas in painter coordinates Implements QwtPolarItem. Definition at line 177 of file qwt_polar_spectrogram.cpp. QImage QwtPolarSpectrogram::renderImage (const QwtScaleMap & azimuthMap, const QwtScaleMap & radialMap, const QPointF & pole, const QRect & rect) const [protected], [virtual] Render an image from the data and color map. The area is translated into a rect of the paint device. For each pixel of this rect the intensity is mapped into a color. Parameters azimuthMap Maps azimuth values to values related to 0.0, M_2PI radialMap Maps radius values into painter coordinates. pole Position of the pole in painter coordinates rect Target rectangle of the image in painter coordinates Returns A QImage::Format_Indexed8 or QImage::Format_ARGB32 depending on the color map. See also QwtRasterData::intensity(), QwtColorMap::rgb(), QwtColorMap::colorIndex() Definition at line 235 of file qwt_polar_spectrogram.cpp. void QwtPolarSpectrogram::renderTile (const QwtScaleMap & azimuthMap, const QwtScaleMap & radialMap, const QPointF & pole, const QPoint & imagePos, const QRect & tile, QImage * image) const [protected], [virtual] Render a sub-rectangle of an image. renderTile() is called by renderImage() to render different parts of the image by concurrent threads. Parameters azimuthMap Maps azimuth values to values related to 0.0, M_2PI radialMap Maps radius values into painter coordinates. pole Position of the pole in painter coordinates imagePos Top/left position of the image in painter coordinates tile Sub-rectangle of the tile in painter coordinates image Image to be rendered See also setRenderThreadCount() Note renderTile needs to be reentrant Definition at line 343 of file qwt_polar_spectrogram.cpp. int QwtPolarSpectrogram::rtti () const [override], [virtual] Returns QwtPolarItem::Rtti_PolarSpectrogram Reimplemented from QwtPolarItem. Definition at line 76 of file qwt_polar_spectrogram.cpp. void QwtPolarSpectrogram::setColorMap (QwtColorMap * colorMap) Change the color map Often it is useful to display the mapping between intensities and colors as an additional plot axis, showing a color bar. Parameters colorMap Color Map See also colorMap(), QwtScaleWidget::setColorBarEnabled(), QwtScaleWidget::setColorMap() Definition at line 122 of file qwt_polar_spectrogram.cpp. void QwtPolarSpectrogram::setData (QwtRasterData * data) Set the data to be displayed Parameters data Spectrogram Data See also data() Warning QwtRasterData::initRaster() is called each time before the image is rendered, but without any useful parameters. Also QwtRasterData::rasterHint() is not used. Definition at line 91 of file qwt_polar_spectrogram.cpp. void QwtPolarSpectrogram::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 149 of file qwt_polar_spectrogram.cpp. bool QwtPolarSpectrogram::testPaintAttribute (PaintAttribute attribute) const Parameters attribute Paint attribute Returns True, when attribute has been set See also setPaintAttribute() Definition at line 162 of file qwt_polar_spectrogram.cpp. Author Generated automatically by Doxygen for Qwt User's Guide from the source code. Version 6.2.0 Sun Jul 18 2021 QwtPolarSpectrogram(3)