.TH "QwtPlotSpectrogram" 3 "Sun Jul 18 2021" "Version 6.2.0" "Qwt User's Guide" \" -*- nroff -*-
.ad l
.nh
.SH NAME
QwtPlotSpectrogram \- A plot item, which displays a spectrogram\&.  

.SH SYNOPSIS
.br
.PP
.PP
\fC#include <qwt_plot_spectrogram\&.h>\fP
.PP
Inherits \fBQwtPlotRasterItem\fP\&.
.SS "Public Types"

.in +1c
.ti -1c
.RI "enum \fBDisplayMode\fP { \fBImageMode\fP = 0x01, \fBContourMode\fP = 0x02 }"
.br
.ti -1c
.RI "typedef QFlags< \fBDisplayMode\fP > \fBDisplayModes\fP"
.br
.in -1c
.SS "Public Member Functions"

.in +1c
.ti -1c
.RI "\fBQwtPlotSpectrogram\fP (const QString &\fBtitle\fP=QString())"
.br
.ti -1c
.RI "virtual \fB~QwtPlotSpectrogram\fP ()"
.br
.RI "Destructor\&. "
.ti -1c
.RI "void \fBsetDisplayMode\fP (\fBDisplayMode\fP, bool on=true)"
.br
.ti -1c
.RI "bool \fBtestDisplayMode\fP (\fBDisplayMode\fP) const"
.br
.ti -1c
.RI "void \fBsetData\fP (\fBQwtRasterData\fP *\fBdata\fP)"
.br
.ti -1c
.RI "const \fBQwtRasterData\fP * \fBdata\fP () const"
.br
.ti -1c
.RI "\fBQwtRasterData\fP * \fBdata\fP ()"
.br
.ti -1c
.RI "void \fBsetColorMap\fP (\fBQwtColorMap\fP *)"
.br
.ti -1c
.RI "const \fBQwtColorMap\fP * \fBcolorMap\fP () const"
.br
.ti -1c
.RI "void \fBsetColorTableSize\fP (int numColors)"
.br
.ti -1c
.RI "int \fBcolorTableSize\fP () const"
.br
.ti -1c
.RI "virtual \fBQwtInterval\fP \fBinterval\fP (Qt::Axis) const override"
.br
.ti -1c
.RI "virtual QRectF \fBpixelHint\fP (const QRectF &) const override"
.br
.RI "Pixel hint\&. "
.ti -1c
.RI "void \fBsetDefaultContourPen\fP (const QColor &, qreal width=0\&.0, Qt::PenStyle=Qt::SolidLine)"
.br
.ti -1c
.RI "void \fBsetDefaultContourPen\fP (const QPen &)"
.br
.RI "Set the default pen for the contour lines\&. "
.ti -1c
.RI "QPen \fBdefaultContourPen\fP () const"
.br
.ti -1c
.RI "virtual QPen \fBcontourPen\fP (double level) const"
.br
.RI "Calculate the pen for a contour line\&. "
.ti -1c
.RI "void \fBsetConrecFlag\fP (\fBQwtRasterData::ConrecFlag\fP, bool on)"
.br
.ti -1c
.RI "bool \fBtestConrecFlag\fP (\fBQwtRasterData::ConrecFlag\fP) const"
.br
.ti -1c
.RI "void \fBsetContourLevels\fP (const \fBQList\fP< double > &)"
.br
.ti -1c
.RI "\fBQList\fP< double > \fBcontourLevels\fP () const"
.br
.ti -1c
.RI "virtual int \fBrtti\fP () const override"
.br
.ti -1c
.RI "virtual void \fBdraw\fP (QPainter *, const \fBQwtScaleMap\fP &xMap, const \fBQwtScaleMap\fP &yMap, const QRectF &canvasRect) const override"
.br
.RI "Draw the spectrogram\&. "
.in -1c
.SS "Protected Member Functions"

.in +1c
.ti -1c
.RI "virtual QImage \fBrenderImage\fP (const \fBQwtScaleMap\fP &xMap, const \fBQwtScaleMap\fP &yMap, const QRectF &area, const QSize &imageSize) const override"
.br
.RI "Render an image from data and color map\&. "
.ti -1c
.RI "virtual QSize \fBcontourRasterSize\fP (const QRectF &, const QRect &) const"
.br
.RI "Return the raster to be used by the CONREC contour algorithm\&. "
.ti -1c
.RI "virtual \fBQwtRasterData::ContourLines\fP \fBrenderContourLines\fP (const QRectF &rect, const QSize &raster) const"
.br
.ti -1c
.RI "virtual void \fBdrawContourLines\fP (QPainter *, const \fBQwtScaleMap\fP &xMap, const \fBQwtScaleMap\fP &yMap, const \fBQwtRasterData::ContourLines\fP &) const"
.br
.ti -1c
.RI "void \fBrenderTile\fP (const \fBQwtScaleMap\fP &xMap, const \fBQwtScaleMap\fP &yMap, const QRect &tile, QImage *) const"
.br
.RI "Render a tile of an image\&. "
.in -1c
.SH "Detailed Description"
.PP 
A plot 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\&.
.PP
On multi-core systems the performance of the image composition can often be improved by dividing the area into tiles - each of them rendered in a different thread ( see \fBQwtPlotItem::setRenderThreadCount()\fP )\&.
.PP
In ContourMode contour lines are painted for the contour levels\&.
.PP
\fBSee also\fP
.RS 4
\fBQwtRasterData\fP, \fBQwtColorMap\fP, \fBQwtPlotItem::setRenderThreadCount()\fP 
.RE
.PP

.PP
Definition at line 36 of file qwt_plot_spectrogram\&.h\&.
.SH "Member Typedef Documentation"
.PP 
.SS "typedef QFlags<\fBDisplayMode\fP > \fBQwtPlotSpectrogram::DisplayModes\fP"
An ORed combination of \fBDisplayMode\fP values\&. 
.PP
Definition at line 53 of file qwt_plot_spectrogram\&.h\&.
.SH "Member Enumeration Documentation"
.PP 
.SS "enum \fBQwtPlotSpectrogram::DisplayMode\fP"
The display mode controls how the raster data will be represented\&. 
.PP
\fBSee also\fP
.RS 4
\fBsetDisplayMode()\fP, \fBtestDisplayMode()\fP 
.RE
.PP

.PP
\fBEnumerator\fP
.in +1c
.TP
\fB\fIImageMode \fP\fP
The values are mapped to colors using a color map\&. 
.TP
\fB\fIContourMode \fP\fP
The data is displayed using contour lines\&. 
.PP
Definition at line 44 of file qwt_plot_spectrogram\&.h\&.
.SH "Constructor & Destructor Documentation"
.PP 
.SS "QwtPlotSpectrogram::QwtPlotSpectrogram (const QString & title = \fCQString()\fP)\fC [explicit]\fP"
Sets the following item attributes:
.IP "\(bu" 2
\fBQwtPlotItem::AutoScale\fP: true
.IP "\(bu" 2
\fBQwtPlotItem::Legend\fP: false
.PP
.PP
The z value is initialized by 8\&.0\&.
.PP
\fBParameters\fP
.RS 4
\fItitle\fP Title
.RE
.PP
\fBSee also\fP
.RS 4
\fBQwtPlotItem::setItemAttribute()\fP, \fBQwtPlotItem::setZ()\fP 
.RE
.PP

.PP
Definition at line 108 of file qwt_plot_spectrogram\&.cpp\&.
.SH "Member Function Documentation"
.PP 
.SS "const \fBQwtColorMap\fP * QwtPlotSpectrogram::colorMap () const"

.PP
\fBReturns\fP
.RS 4
Color Map used for mapping the intensity values to colors 
.RE
.PP
\fBSee also\fP
.RS 4
\fBsetColorMap()\fP 
.RE
.PP

.PP
Definition at line 200 of file qwt_plot_spectrogram\&.cpp\&.
.SS "int QwtPlotSpectrogram::colorTableSize () const"

.PP
\fBReturns\fP
.RS 4
Size of the color table, 0 means not using a color table 
.RE
.PP
\fBSee also\fP
.RS 4
\fBQwtColorMap::colorTable()\fP, \fBsetColorTableSize()\fP 
.RE
.PP

.PP
Definition at line 238 of file qwt_plot_spectrogram\&.cpp\&.
.SS "\fBQList\fP< double > QwtPlotSpectrogram::contourLevels () const"

.PP
\fBReturns\fP
.RS 4
Levels of the contour lines\&.
.RE
.PP
The levels are sorted in increasing order\&.
.PP
\fBSee also\fP
.RS 4
\fBcontourLevels()\fP, \fBrenderContourLines()\fP, \fBQwtRasterData::contourLines()\fP 
.RE
.PP

.PP
Definition at line 382 of file qwt_plot_spectrogram\&.cpp\&.
.SS "QPen QwtPlotSpectrogram::contourPen (double level) const\fC [virtual]\fP"

.PP
Calculate the pen for a contour line\&. The color of the pen is the color for level calculated by the color map
.PP
\fBParameters\fP
.RS 4
\fIlevel\fP Contour level 
.RE
.PP
\fBReturns\fP
.RS 4
Pen for the contour line 
.RE
.PP
\fBNote\fP
.RS 4
contourPen is only used if \fBdefaultContourPen()\fP\&.style() == Qt::NoPen
.RE
.PP
\fBSee also\fP
.RS 4
\fBsetDefaultContourPen()\fP, \fBsetColorMap()\fP, \fBsetContourLevels()\fP 
.RE
.PP

.PP
Definition at line 303 of file qwt_plot_spectrogram\&.cpp\&.
.SS "QSize QwtPlotSpectrogram::contourRasterSize (const QRectF & area, const QRect & rect) const\fC [protected]\fP, \fC [virtual]\fP"

.PP
Return the raster to be used by the CONREC contour algorithm\&. A larger size will improve the precision of the CONREC algorithm, but will slow down the time that is needed to calculate the lines\&.
.PP
The default implementation returns rect\&.size() / 2 bounded to the resolution depending on pixelSize()\&.
.PP
\fBParameters\fP
.RS 4
\fIarea\fP Rectangle, where to calculate the contour lines 
.br
\fIrect\fP Rectangle in pixel coordinates, where to paint the contour lines 
.RE
.PP
\fBReturns\fP
.RS 4
Raster to be used by the CONREC contour algorithm\&.
.RE
.PP
\fBNote\fP
.RS 4
The size will be bounded to rect\&.size()\&.
.RE
.PP
\fBSee also\fP
.RS 4
\fBdrawContourLines()\fP, \fBQwtRasterData::contourLines()\fP 
.RE
.PP

.PP
Definition at line 663 of file qwt_plot_spectrogram\&.cpp\&.
.SS "\fBQwtRasterData\fP * QwtPlotSpectrogram::data ()"

.PP
\fBReturns\fP
.RS 4
Spectrogram data 
.RE
.PP
\fBSee also\fP
.RS 4
\fBsetData()\fP 
.RE
.PP

.PP
Definition at line 418 of file qwt_plot_spectrogram\&.cpp\&.
.SS "const \fBQwtRasterData\fP * QwtPlotSpectrogram::data () const"

.PP
\fBReturns\fP
.RS 4
Spectrogram data 
.RE
.PP
\fBSee also\fP
.RS 4
\fBsetData()\fP 
.RE
.PP

.PP
Definition at line 409 of file qwt_plot_spectrogram\&.cpp\&.
.SS "QPen QwtPlotSpectrogram::defaultContourPen () const"

.PP
\fBReturns\fP
.RS 4
Default contour pen 
.RE
.PP
\fBSee also\fP
.RS 4
\fBsetDefaultContourPen()\fP 
.RE
.PP

.PP
Definition at line 287 of file qwt_plot_spectrogram\&.cpp\&.
.SS "void QwtPlotSpectrogram::draw (QPainter * painter, const \fBQwtScaleMap\fP & xMap, const \fBQwtScaleMap\fP & yMap, const QRectF & canvasRect) const\fC [override]\fP, \fC [virtual]\fP"

.PP
Draw the spectrogram\&. 
.PP
\fBParameters\fP
.RS 4
\fIpainter\fP Painter 
.br
\fIxMap\fP Maps x-values into pixel coordinates\&. 
.br
\fIyMap\fP Maps y-values into pixel coordinates\&. 
.br
\fIcanvasRect\fP Contents rectangle of the canvas in painter coordinates
.RE
.PP
\fBSee also\fP
.RS 4
\fBsetDisplayMode()\fP, \fBrenderImage()\fP, \fBQwtPlotRasterItem::draw()\fP, \fBdrawContourLines()\fP 
.RE
.PP

.PP
Reimplemented from \fBQwtPlotRasterItem\fP\&.
.PP
Definition at line 754 of file qwt_plot_spectrogram\&.cpp\&.
.SS "void QwtPlotSpectrogram::drawContourLines (QPainter * painter, const \fBQwtScaleMap\fP & xMap, const \fBQwtScaleMap\fP & yMap, const \fBQwtRasterData::ContourLines\fP & contourLines) const\fC [protected]\fP, \fC [virtual]\fP"
Paint the contour lines
.PP
\fBParameters\fP
.RS 4
\fIpainter\fP Painter 
.br
\fIxMap\fP Maps x-values into pixel coordinates\&. 
.br
\fIyMap\fP Maps y-values into pixel coordinates\&. 
.br
\fIcontourLines\fP Contour lines
.RE
.PP
\fBSee also\fP
.RS 4
\fBrenderContourLines()\fP, \fBdefaultContourPen()\fP, \fBcontourPen()\fP 
.RE
.PP

.PP
Definition at line 709 of file qwt_plot_spectrogram\&.cpp\&.
.SS "\fBQwtInterval\fP QwtPlotSpectrogram::interval (Qt::Axis axis) const\fC [override]\fP, \fC [virtual]\fP"

.PP
\fBReturns\fP
.RS 4
Bounding interval for an axis
.RE
.PP
The default implementation returns the interval of the associated raster data object\&.
.PP
\fBParameters\fP
.RS 4
\fIaxis\fP X, Y, or Z axis 
.RE
.PP
\fBSee also\fP
.RS 4
\fBQwtRasterData::interval()\fP 
.RE
.PP

.PP
Reimplemented from \fBQwtPlotRasterItem\fP\&.
.PP
Definition at line 432 of file qwt_plot_spectrogram\&.cpp\&.
.SS "QRectF QwtPlotSpectrogram::pixelHint (const QRectF & area) const\fC [override]\fP, \fC [virtual]\fP"

.PP
Pixel hint\&. The geometry of a pixel is used to calculated the resolution and alignment of the rendered image\&.
.PP
The default implementation returns \fBdata()\fP->pixelHint( rect );
.PP
\fBParameters\fP
.RS 4
\fIarea\fP In most implementations the resolution of the data doesn't depend on the requested area\&.
.RE
.PP
\fBReturns\fP
.RS 4
Bounding rectangle of a pixel
.RE
.PP
\fBSee also\fP
.RS 4
\fBQwtPlotRasterItem::pixelHint()\fP, \fBQwtRasterData::pixelHint()\fP, render(), \fBrenderImage()\fP 
.RE
.PP

.PP
Reimplemented from \fBQwtPlotRasterItem\fP\&.
.PP
Definition at line 456 of file qwt_plot_spectrogram\&.cpp\&.
.SS "\fBQwtRasterData::ContourLines\fP QwtPlotSpectrogram::renderContourLines (const QRectF & rect, const QSize & raster) const\fC [protected]\fP, \fC [virtual]\fP"
Calculate contour lines
.PP
\fBParameters\fP
.RS 4
\fIrect\fP Rectangle, where to calculate the contour lines 
.br
\fIraster\fP Raster, used by the CONREC algorithm 
.RE
.PP
\fBReturns\fP
.RS 4
Calculated contour lines
.RE
.PP
\fBSee also\fP
.RS 4
\fBcontourLevels()\fP, \fBsetConrecFlag()\fP, \fBQwtRasterData::contourLines()\fP 
.RE
.PP

.PP
Definition at line 689 of file qwt_plot_spectrogram\&.cpp\&.
.SS "QImage QwtPlotSpectrogram::renderImage (const \fBQwtScaleMap\fP & xMap, const \fBQwtScaleMap\fP & yMap, const QRectF & area, const QSize & imageSize) const\fC [override]\fP, \fC [protected]\fP, \fC [virtual]\fP"

.PP
Render an image from data and color map\&. For each pixel of area the value is mapped into a color\&.
.PP
\fBParameters\fP
.RS 4
\fIxMap\fP X-Scale Map 
.br
\fIyMap\fP Y-Scale Map 
.br
\fIarea\fP Requested area for the image in scale coordinates 
.br
\fIimageSize\fP Size of the requested image
.RE
.PP
\fBReturns\fP
.RS 4
A QImage::Format_Indexed8 or QImage::Format_ARGB32 depending on the color map\&.
.RE
.PP
\fBSee also\fP
.RS 4
\fBQwtRasterData::value()\fP, \fBQwtColorMap::rgb()\fP, \fBQwtColorMap::colorIndex()\fP 
.RE
.PP

.PP
Implements \fBQwtPlotRasterItem\fP\&.
.PP
Definition at line 480 of file qwt_plot_spectrogram\&.cpp\&.
.SS "void QwtPlotSpectrogram::renderTile (const \fBQwtScaleMap\fP & xMap, const \fBQwtScaleMap\fP & yMap, const QRect & tile, QImage * image) const\fC [protected]\fP"

.PP
Render a tile of an image\&. Rendering in tiles can be used to composite an image in parallel threads\&.
.PP
\fBParameters\fP
.RS 4
\fIxMap\fP X-Scale Map 
.br
\fIyMap\fP Y-Scale Map 
.br
\fItile\fP Geometry of the tile in image coordinates 
.br
\fIimage\fP Image to be rendered 
.RE
.PP

.PP
Definition at line 572 of file qwt_plot_spectrogram\&.cpp\&.
.SS "int QwtPlotSpectrogram::rtti () const\fC [override]\fP, \fC [virtual]\fP"

.PP
\fBReturns\fP
.RS 4
\fBQwtPlotItem::Rtti_PlotSpectrogram\fP 
.RE
.PP

.PP
Reimplemented from \fBQwtPlotItem\fP\&.
.PP
Definition at line 126 of file qwt_plot_spectrogram\&.cpp\&.
.SS "void QwtPlotSpectrogram::setColorMap (\fBQwtColorMap\fP * colorMap)"
Change the color map
.PP
Often it is useful to display the mapping between intensities and colors as an additional plot axis, showing a color bar\&.
.PP
\fBParameters\fP
.RS 4
\fIcolorMap\fP Color Map
.RE
.PP
\fBSee also\fP
.RS 4
\fBcolorMap()\fP, \fBQwtScaleWidget::setColorBarEnabled()\fP, \fBQwtScaleWidget::setColorMap()\fP 
.RE
.PP

.PP
Definition at line 177 of file qwt_plot_spectrogram\&.cpp\&.
.SS "void QwtPlotSpectrogram::setColorTableSize (int numColors)"
Limit the number of colors being used by the color map
.PP
When using a color table the mapping from the value into a color is usually faster as it can be done by simple lookups into a precalculated color table\&.
.PP
Setting a table size > 0 enables using a color table, while setting the size to 0 disables it\&.
.PP
The default size = 0, and no color table is used\&.
.PP
\fBParameters\fP
.RS 4
\fInumColors\fP Number of colors\&. 0 means not using a color table 
.RE
.PP
\fBNote\fP
.RS 4
The colorTableSize has no effect when using a color table of \fBQwtColorMap::Indexed\fP, where the size is always 256\&.
.RE
.PP
\fBSee also\fP
.RS 4
\fBQwtColorMap::colorTable()\fP, \fBcolorTableSize()\fP 
.RE
.PP

.PP
Definition at line 224 of file qwt_plot_spectrogram\&.cpp\&.
.SS "void QwtPlotSpectrogram::setConrecFlag (\fBQwtRasterData::ConrecFlag\fP flag, bool on)"
Modify an attribute of the CONREC algorithm, used to calculate the contour lines\&.
.PP
\fBParameters\fP
.RS 4
\fIflag\fP CONREC flag 
.br
\fIon\fP On/Off
.RE
.PP
\fBSee also\fP
.RS 4
\fBtestConrecFlag()\fP, \fBrenderContourLines()\fP, \fBQwtRasterData::contourLines()\fP 
.RE
.PP

.PP
Definition at line 324 of file qwt_plot_spectrogram\&.cpp\&.
.SS "void QwtPlotSpectrogram::setContourLevels (const \fBQList\fP< double > & levels)"
Set the levels of the contour lines
.PP
\fBParameters\fP
.RS 4
\fIlevels\fP Values of the contour levels 
.RE
.PP
\fBSee also\fP
.RS 4
\fBcontourLevels()\fP, \fBrenderContourLines()\fP, \fBQwtRasterData::contourLines()\fP
.RE
.PP
\fBNote\fP
.RS 4
contourLevels returns the same levels but sorted\&. 
.RE
.PP

.PP
Definition at line 365 of file qwt_plot_spectrogram\&.cpp\&.
.SS "void QwtPlotSpectrogram::setData (\fBQwtRasterData\fP * data)"
Set the data to be displayed
.PP
\fBParameters\fP
.RS 4
\fIdata\fP Spectrogram Data 
.RE
.PP
\fBSee also\fP
.RS 4
\fBdata()\fP 
.RE
.PP

.PP
Definition at line 393 of file qwt_plot_spectrogram\&.cpp\&.
.SS "void QwtPlotSpectrogram::setDefaultContourPen (const QColor & color, qreal width = \fC0\&.0\fP, Qt::PenStyle style = \fCQt::SolidLine\fP)"
Build and assign the default pen for the contour lines
.PP
In Qt5 the default pen width is 1\&.0 ( 0\&.0 in Qt4 ) what makes it non cosmetic ( see QPen::isCosmetic() )\&. This method has been introduced to hide this incompatibility\&.
.PP
\fBParameters\fP
.RS 4
\fIcolor\fP Pen color 
.br
\fIwidth\fP Pen width 
.br
\fIstyle\fP Pen style
.RE
.PP
\fBSee also\fP
.RS 4
pen(), brush() 
.RE
.PP

.PP
Definition at line 256 of file qwt_plot_spectrogram\&.cpp\&.
.SS "void QwtPlotSpectrogram::setDefaultContourPen (const QPen & pen)"

.PP
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 \fBcontourPen()\fP\&.
.PP
\fBSee also\fP
.RS 4
\fBdefaultContourPen()\fP, \fBcontourPen()\fP 
.RE
.PP

.PP
Definition at line 272 of file qwt_plot_spectrogram\&.cpp\&.
.SS "void QwtPlotSpectrogram::setDisplayMode (\fBDisplayMode\fP mode, bool on = \fCtrue\fP)"
The display mode controls how the raster data will be represented\&.
.PP
\fBParameters\fP
.RS 4
\fImode\fP Display mode 
.br
\fIon\fP On/Off
.RE
.PP
The default setting enables ImageMode\&.
.PP
\fBSee also\fP
.RS 4
\fBDisplayMode\fP, displayMode() 
.RE
.PP

.PP
Definition at line 141 of file qwt_plot_spectrogram\&.cpp\&.
.SS "bool QwtPlotSpectrogram::testConrecFlag (\fBQwtRasterData::ConrecFlag\fP flag) const"
Test an attribute of the CONREC algorithm, used to calculate the contour lines\&.
.PP
\fBParameters\fP
.RS 4
\fIflag\fP CONREC flag 
.RE
.PP
\fBReturns\fP
.RS 4
true, is enabled
.RE
.PP
The default setting enables \fBQwtRasterData::IgnoreAllVerticesOnLevel\fP
.PP
\fBSee also\fP
.RS 4
setConrecClag(), \fBrenderContourLines()\fP, \fBQwtRasterData::contourLines()\fP 
.RE
.PP

.PP
Definition at line 350 of file qwt_plot_spectrogram\&.cpp\&.
.SS "bool QwtPlotSpectrogram::testDisplayMode (\fBDisplayMode\fP mode) const"
The display mode controls how the raster data will be represented\&.
.PP
\fBParameters\fP
.RS 4
\fImode\fP Display mode 
.RE
.PP
\fBReturns\fP
.RS 4
true if mode is enabled 
.RE
.PP

.PP
Definition at line 161 of file qwt_plot_spectrogram\&.cpp\&.

.SH "Author"
.PP 
Generated automatically by Doxygen for Qwt User's Guide from the source code\&.