Qwt User's Guide  6.0.2
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 = 0x01,
  ContourMode = 0x02
}
typedef QFlags< DisplayMode > DisplayModes
- Public Types inherited from QwtPlotRasterItem
enum  CachePolicy {
  NoCache,
  PaintCache
}
enum  PaintAttribute { PaintInDeviceResolution = 1 }
typedef QFlags< PaintAttribute > PaintAttributes
- Public Types inherited from QwtPlotItem
enum  ItemAttribute {
  Legend = 0x01,
  AutoScale = 0x02
}
typedef QFlags< ItemAttribute > ItemAttributes
enum  RenderHint { RenderAntialiased = 1 }
typedef QFlags< RenderHint > RenderHints
enum  RttiValues {
  Rtti_PlotItem = 0,
  Rtti_PlotGrid,
  Rtti_PlotScale,
  Rtti_PlotMarker,
  Rtti_PlotCurve,
  Rtti_PlotSpectroCurve,
  Rtti_PlotIntervalCurve,
  Rtti_PlotHistogram,
  Rtti_PlotSpectrogram,
  Rtti_PlotSVG,
  Rtti_PlotUserItem = 1000
}

Public Member Functions

 QwtPlotSpectrogram (const QString &title=QString::null)
virtual ~QwtPlotSpectrogram ()
const QwtColorMap * colorMap () const
QList< double > contourLevels () const
virtual QPen contourPen (double level) const
const QwtRasterData * data () const
QwtRasterData * data ()
QPen defaultContourPen () const
virtual void draw (QPainter *p, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &rect) const
virtual QwtInterval interval (Qt::Axis) const
virtual QRectF pixelHint (const QRectF &) const
uint renderThreadCount () const
virtual int rtti () const
void setColorMap (QwtColorMap *)
void setConrecFlag (QwtRasterData::ConrecFlag, bool on)
void setContourLevels (const QList< double > &)
void setData (QwtRasterData *data)
void setDefaultContourPen (const QPen &)
void setDisplayMode (DisplayMode, bool on=true)
void setRenderThreadCount (uint numThreads)
bool testConrecFlag (QwtRasterData::ConrecFlag) 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
virtual QRectF boundingRect () const
CachePolicy cachePolicy () const
void invalidateCache ()
void setAlpha (int alpha)
void setCachePolicy (CachePolicy)
void setPaintAttribute (PaintAttribute, bool on=true)
bool testPaintAttribute (PaintAttribute) const
- Public Member Functions inherited from QwtPlotItem
 QwtPlotItem (const QwtText &title=QwtText())
virtual ~QwtPlotItem ()
void attach (QwtPlot *plot)
void detach ()
void hide ()
bool isVisible () const
virtual void itemChanged ()
virtual QWidget * legendItem () const
QRectF paintRect (const QwtScaleMap &, const QwtScaleMap &) const
QwtPlot * plot () const
QRectF scaleRect (const QwtScaleMap &, const QwtScaleMap &) const
void setAxes (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 QwtText & title () 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 ()
virtual void drawLegendIdentifier (QPainter *, const QRectF &) const

Protected Member Functions

virtual QSize contourRasterSize (const QRectF &, const QRect &) const
virtual void drawContourLines (QPainter *p, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QwtRasterData::ContourLines &lines) const
virtual QwtRasterData::ContourLines renderContourLines (const QRectF &rect, const QSize &raster) const
virtual QImage renderImage (const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &area, const QSize &imageSize) const
void renderTile (const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRect &imageRect, QImage *image) const
- Protected Member Functions inherited from QwtPlotRasterItem
virtual QwtScaleMap imageMap (Qt::Orientation, const QwtScaleMap &map, const QRectF &area, const QSize &imageSize, double pixelSize) 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.

See also:
setDisplayMode(), testDisplayMode()
Enumerator:
ImageMode 

The values are mapped to colors using a color map.

ContourMode 

The data is displayed using contour lines.


Constructor & Destructor Documentation

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

Sets the following item attributes:

The z value is initialized by 8.0.

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

Member Function Documentation

const QwtColorMap * QwtPlotSpectrogram::colorMap ( ) const
Returns:
Color Map used for mapping the intensity values to colors
See also:
setColorMap()
QList< double > 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 QRectF &  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 the resolution depending on pixelSize().

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()
QwtRasterData * QwtPlotSpectrogram::data ( )
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 QRectF &  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()
QwtInterval QwtPlotSpectrogram::interval ( Qt::Axis  axis) const
virtual
Returns:
Bounding interval for an axis

The default implementation returns the interval of the associated raster data object.

Parameters:
axisX, Y, or Z axis
See also:
QwtRasterData::interval()

Reimplemented from QwtPlotRasterItem.

QRectF QwtPlotSpectrogram::pixelHint ( const QRectF &  area) const
virtual

Pixel hint.

The geometry of a pixel is used to calculated the resolution and alignment of the rendered image.

The default implementation returns data()->pixelHint( rect );

Parameters:
areaIn most implementations the resolution of the data doesn't depend on the requested area.
Returns:
Bounding rectangle of a pixel
See also:
QwtPlotRasterItem::pixelHint(), QwtRasterData::pixelHint(), render(), renderImage()

Reimplemented from QwtPlotRasterItem.

QwtRasterData::ContourLines QwtPlotSpectrogram::renderContourLines ( const QRectF &  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(), setConrecFlag(), QwtRasterData::contourLines()
QImage QwtPlotSpectrogram::renderImage ( const QwtScaleMap &  xMap,
const QwtScaleMap &  yMap,
const QRectF &  area,
const QSize &  imageSize 
) const
protectedvirtual

Render an image from data and color map.

For each pixel of rect the value is mapped into a color.

Parameters:
xMapX-Scale Map
yMapY-Scale Map
areaRequested area for the image in scale coordinates
imageSizeSize of the requested image
Returns:
A QImage::Format_Indexed8 or QImage::Format_ARGB32 depending on the color map.
See also:
QwtRasterData::value(), QwtColorMap::rgb(), QwtColorMap::colorIndex()

Implements QwtPlotRasterItem.

uint QwtPlotSpectrogram::renderThreadCount ( ) const
Returns:
Number of threads to be used for rendering. If numThreads is set to 0, the system specific ideal thread count is used.
Warning:
Rendering in multiple threads is only supported for Qt >= 4.4
See also:
setRenderThreadCount(), renderImage(), renderTile()
void QwtPlotSpectrogram::renderTile ( const QwtScaleMap &  xMap,
const QwtScaleMap &  yMap,
const QRect &  tile,
QImage *  image 
) const
protected

Render a tile of an image.

Rendering in tiles can be used to composite an image in parallel threads.

Parameters:
xMapX-Scale Map
yMapY-Scale Map
tileGeometry of the tile in image coordinates
imageImage to be rendered
int QwtPlotSpectrogram::rtti ( ) const
virtual
Returns:
QwtPlotItem::Rtti_PlotSpectrogram

Reimplemented from QwtPlotItem.

void QwtPlotSpectrogram::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:
colorMapColor Map
See also:
colorMap(), QwtScaleWidget::setColorBarEnabled(), QwtScaleWidget::setColorMap()
void QwtPlotSpectrogram::setConrecFlag ( QwtRasterData::ConrecFlag  flag,
bool  on 
)

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

Parameters:
flagCONREC flag
onOn/Off
See also:
testConrecFlag(), renderContourLines(), QwtRasterData::contourLines()
void QwtPlotSpectrogram::setContourLevels ( const QList< double > &  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 ( 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()
void QwtPlotSpectrogram::setRenderThreadCount ( uint  numThreads)

Rendering an image from the raster data can often be done parallel on a multicore system.

Parameters:
numThreadsNumber of threads to be used for rendering. If numThreads is set to 0, the system specific ideal thread count is used.

The default thread count is 1 ( = no additional threads )

Warning:
Rendering in multiple threads is only supported for Qt >= 4.4
See also:
renderThreadCount(), renderImage(), renderTile()
bool QwtPlotSpectrogram::testConrecFlag ( QwtRasterData::ConrecFlag  flag) const

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

Parameters:
flagCONREC flag
Returns:
true, is enabled
See also:
setConrecClag(), 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