Qwt User's Guide  5.2.3
Public Types | Public Member Functions | Protected Member Functions
QwtPlotSpectrogram Class Reference

#include <qwt_plot_spectrogram.h>

Inheritance diagram for QwtPlotSpectrogram:
Inheritance graph
[legend]

List of all members.

Public Types

enum  DisplayMode {
  ImageMode = 1,
  ContourMode = 2
}
- Public Types inherited from QwtPlotRasterItem
enum  CachePolicy {
  NoCache,
  PaintCache,
  ScreenCache
}
- Public Types inherited from QwtPlotItem
enum  ItemAttribute {
  Legend = 1,
  AutoScale = 2
}
enum  RenderHint { RenderAntialiased = 1 }
enum  RttiValues {
  Rtti_PlotItem = 0,
  Rtti_PlotGrid,
  Rtti_PlotScale,
  Rtti_PlotMarker,
  Rtti_PlotCurve,
  Rtti_PlotHistogram,
  Rtti_PlotSpectrogram,
  Rtti_PlotSVG,
  Rtti_PlotUserItem = 1000
}

Public Member Functions

 QwtPlotSpectrogram (const QString &title=QString::null)
virtual ~QwtPlotSpectrogram ()
virtual QwtDoubleRect boundingRect () const
const QwtColorMapcolorMap () const
QwtValueList contourLevels () const
virtual QPen contourPen (double level) const
const QwtRasterDatadata () const
QPen defaultContourPen () const
virtual void draw (QPainter *p, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRect &rect) const
virtual QSize rasterHint (const QwtDoubleRect &) const
virtual int rtti () const
void setColorMap (const QwtColorMap &)
void setConrecAttribute (QwtRasterData::ConrecAttribute, bool on)
void setContourLevels (const QwtValueList &)
void setData (const QwtRasterData &data)
void setDefaultContourPen (const QPen &)
void setDisplayMode (DisplayMode, bool on=true)
bool testConrecAttribute (QwtRasterData::ConrecAttribute) const
bool testDisplayMode (DisplayMode) const
- Public Member Functions inherited from QwtPlotRasterItem
 QwtPlotRasterItem (const QString &title=QString::null)
 QwtPlotRasterItem (const QwtText &title)
virtual ~QwtPlotRasterItem ()
int alpha () const
CachePolicy cachePolicy () const
void invalidateCache ()
void setAlpha (int alpha)
void setCachePolicy (CachePolicy)
- Public Member Functions inherited from QwtPlotItem
 QwtPlotItem (const QwtText &title=QwtText())
virtual ~QwtPlotItem ()
void attach (QwtPlot *plot)
void detach ()
void hide ()
QwtDoubleRect invTransform (const QwtScaleMap &, const QwtScaleMap &, const QRect &) const
bool isVisible () const
virtual void itemChanged ()
virtual QWidget * legendItem () const
QRect paintRect (const QwtScaleMap &, const QwtScaleMap &) const
QwtPlotplot () const
QwtDoubleRect scaleRect (const QwtScaleMap &, const QwtScaleMap &) const
void setAxis (int xAxis, int yAxis)
void setItemAttribute (ItemAttribute, bool on=true)
void setRenderHint (RenderHint, bool on=true)
void setTitle (const QString &title)
void setTitle (const QwtText &title)
virtual void setVisible (bool)
void setXAxis (int axis)
void setYAxis (int axis)
void setZ (double z)
void show ()
bool testItemAttribute (ItemAttribute) const
bool testRenderHint (RenderHint) const
const QwtTexttitle () const
QRect transform (const QwtScaleMap &, const QwtScaleMap &, const QwtDoubleRect &) const
virtual void updateLegend (QwtLegend *) const
virtual void updateScaleDiv (const QwtScaleDiv &, const QwtScaleDiv &)
int xAxis () const
int yAxis () const
double z () const
- Public Member Functions inherited from QwtLegendItemManager
 QwtLegendItemManager ()
virtual ~QwtLegendItemManager ()

Protected Member Functions

virtual QSize contourRasterSize (const QwtDoubleRect &, const QRect &) const
virtual void drawContourLines (QPainter *p, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QwtRasterData::ContourLines &lines) const
virtual QwtRasterData::ContourLines renderContourLines (const QwtDoubleRect &rect, const QSize &raster) const
virtual QImage renderImage (const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QwtDoubleRect &rect) const

Detailed Description

A plot item, which displays a spectrogram.

A spectrogram displays threedimenional data, where the 3rd dimension ( the intensity ) is displayed using colors. The colors are calculated from the values using a color map.

In ContourMode contour lines are painted for the contour levels.

spectrogram3.png
See also:
QwtRasterData, QwtColorMap

Member Enumeration Documentation

The display mode controls how the raster data will be represented.

  • ImageMode
    The values are mapped to colors using a color map.
  • ContourMode
    The data is displayed using contour lines

When both modes are enabled the contour lines are painted on top of the spectrogram. The default setting enables ImageMode.

See also:
setDisplayMode(), testDisplayMode()

Constructor & Destructor Documentation

QwtPlotSpectrogram::QwtPlotSpectrogram ( const QString &  title = QString::null)
explicit

Sets the following item attributes:

  • QwtPlotItem::AutoScale: true
  • QwtPlotItem::Legend: false

The z value is initialized by 8.0.

Parameters:
titleTitle
See also:
QwtPlotItem::setItemAttribute(), QwtPlotItem::setZ()

Member Function Documentation

QwtDoubleRect QwtPlotSpectrogram::boundingRect ( ) const
virtual
Returns:
Bounding rect of the data
See also:
QwtRasterData::boundingRect()

Reimplemented from QwtPlotItem.

const QwtColorMap & QwtPlotSpectrogram::colorMap ( ) const
Returns:
Color Map used for mapping the intensity values to colors
See also:
setColorMap()
QwtValueList QwtPlotSpectrogram::contourLevels ( ) const

Return the levels of the contour lines.

The levels are sorted in increasing order.

See also:
contourLevels(), renderContourLines(), QwtRasterData::contourLines()
QPen QwtPlotSpectrogram::contourPen ( double  level) const
virtual

Calculate the pen for a contour line.

The color of the pen is the color for level calculated by the color map

Parameters:
levelContour level
Returns:
Pen for the contour line
Note:
contourPen is only used if defaultContourPen().style() == Qt::NoPen
See also:
setDefaultContourPen(), setColorMap(), setContourLevels()
QSize QwtPlotSpectrogram::contourRasterSize ( const QwtDoubleRect &  area,
const QRect &  rect 
) const
protectedvirtual

Return the raster to be used by the CONREC contour algorithm.

A larger size will improve the precisision of the CONREC algorithm, but will slow down the time that is needed to calculate the lines.

The default implementation returns rect.size() / 2 bounded to data().rasterHint().

Parameters:
areaRect, where to calculate the contour lines
rectRect in pixel coordinates, where to paint the contour lines
Returns:
Raster to be used by the CONREC contour algorithm.
Note:
The size will be bounded to rect.size().
See also:
drawContourLines(), QwtRasterData::contourLines()
const QwtRasterData & QwtPlotSpectrogram::data ( ) const
Returns:
Spectrogram data
See also:
setData()
QPen QwtPlotSpectrogram::defaultContourPen ( ) const
Returns:
Default contour pen
See also:
setDefaultContourPen()
void QwtPlotSpectrogram::draw ( QPainter *  painter,
const QwtScaleMap xMap,
const QwtScaleMap yMap,
const QRect &  canvasRect 
) const
virtual

Draw the spectrogram.

Parameters:
painterPainter
xMapMaps x-values into pixel coordinates.
yMapMaps y-values into pixel coordinates.
canvasRectContents rect of the canvas in painter coordinates
See also:
setDisplayMode(), renderImage(), QwtPlotRasterItem::draw(), drawContourLines()

Reimplemented from QwtPlotRasterItem.

void QwtPlotSpectrogram::drawContourLines ( QPainter *  painter,
const QwtScaleMap xMap,
const QwtScaleMap yMap,
const QwtRasterData::ContourLines &  contourLines 
) const
protectedvirtual

Paint the contour lines

Parameters:
painterPainter
xMapMaps x-values into pixel coordinates.
yMapMaps y-values into pixel coordinates.
contourLinesContour lines
See also:
renderContourLines(), defaultContourPen(), contourPen()
QSize QwtPlotSpectrogram::rasterHint ( const QwtDoubleRect &  rect) const
virtual

Returns the recommended raster for a given rect.

F.e the raster hint is used to limit the resolution of the image that is rendered.

Parameters:
rectRect for the raster hint
Returns:
data().rasterHint(rect)

Reimplemented from QwtPlotRasterItem.

QwtRasterData::ContourLines QwtPlotSpectrogram::renderContourLines ( const QwtDoubleRect &  rect,
const QSize &  raster 
) const
protectedvirtual

Calculate contour lines

Parameters:
rectRectangle, where to calculate the contour lines
rasterRaster, used by the CONREC algorithm
See also:
contourLevels(), setConrecAttribute(), QwtRasterData::contourLines()
QImage QwtPlotSpectrogram::renderImage ( const QwtScaleMap xMap,
const QwtScaleMap yMap,
const QwtDoubleRect &  area 
) const
protectedvirtual

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:
xMapX-Scale Map
yMapY-Scale Map
areaArea that should be rendered in scale coordinates.
Returns:
A QImage::Format_Indexed8 or QImage::Format_ARGB32 depending on the color map.
See also:
QwtRasterData::intensity(), QwtColorMap::rgb(), QwtColorMap::colorIndex()

Implements QwtPlotRasterItem.

int QwtPlotSpectrogram::rtti ( ) const
virtual
Returns:
QwtPlotItem::Rtti_PlotSpectrogram

Reimplemented from QwtPlotItem.

void QwtPlotSpectrogram::setColorMap ( const 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:
colorMapColor Map
See also:
colorMap(), QwtScaleWidget::setColorBarEnabled(), QwtScaleWidget::setColorMap()
void QwtPlotSpectrogram::setConrecAttribute ( QwtRasterData::ConrecAttribute  attribute,
bool  on 
)

Modify an attribute of the CONREC algorithm, used to calculate the contour lines.

Parameters:
attributeCONREC attribute
onOn/Off
See also:
testConrecAttribute(), renderContourLines(), QwtRasterData::contourLines()
void QwtPlotSpectrogram::setContourLevels ( const QwtValueList &  levels)

Set the levels of the contour lines

Parameters:
levelsValues of the contour levels
See also:
contourLevels(), renderContourLines(), QwtRasterData::contourLines()
Note:
contourLevels returns the same levels but sorted.
void QwtPlotSpectrogram::setData ( const QwtRasterData data)

Set the data to be displayed

Parameters:
dataSpectrogram Data
See also:
data()
void QwtPlotSpectrogram::setDefaultContourPen ( const QPen &  pen)

Set the default pen for the contour lines.

If the spectrogram has a valid default contour pen a contour line is painted using the default contour pen. Otherwise (pen.style() == Qt::NoPen) the pen is calculated for each contour level using contourPen().

See also:
defaultContourPen(), contourPen()
void QwtPlotSpectrogram::setDisplayMode ( DisplayMode  mode,
bool  on = true 
)

The display mode controls how the raster data will be represented.

Parameters:
modeDisplay mode
onOn/Off

The default setting enables ImageMode.

See also:
DisplayMode, displayMode()
bool QwtPlotSpectrogram::testConrecAttribute ( QwtRasterData::ConrecAttribute  attribute) const

Test an attribute of the CONREC algorithm, used to calculate the contour lines.

Parameters:
attributeCONREC attribute
Returns:
true, is enabled
See also:
setConrecAttribute(), renderContourLines(), QwtRasterData::contourLines()
bool QwtPlotSpectrogram::testDisplayMode ( DisplayMode  mode) const

The display mode controls how the raster data will be represented.

Parameters:
modeDisplay mode
Returns:
true if mode is enabled