problem in plotting QwtMatrixRasterData using QwtPlotSpectrogram

[Uwe]

spectrogram->setXAxis( QwtPlot::XTop );

spectrogram->setXAxis( QwtPlot::XTop );

To copy to clipboard, switch view to plain text mode 

Uwe

[johnMick]

expected_op.jpg
Hi ,
I tried your tip but i didnt get expected result(attached with this reply) code is as below:

#include "plot.h"
#include <qwt_color_map.h>
#include <qwt_plot_spectrogram.h>
#include <qwt_plot_layout.h>
#include <qwt_matrix_raster_data.h>
#include <qwt_scale_widget.h>
#include <qwt_plot_magnifier.h>
#include <qwt_plot_panner.h>
#include <qwt_plot_renderer.h>
#include <qwt_plot_grid.h>
#include <qfiledialog.h>
#include <qimagewriter.h>

class RasterData: public QwtMatrixRasterData
{
public:
RasterData()
{
const double matrix[] =
{
1.0000,0.0443,0.0098,0.0740,0.0030,0.0122,0.0001,
0.0443,1.0000,0.0122,0.0354,0.0013,0.0024,0.0001,
0.0098,0.0122,1.0000,0.1146,0.0520,0.0054,0.0068,
0.0740,0.0354,0.1146,1.0000,0.0131,0.0589,0.0011,
0.0030,0.0013,0.0520,0.0131,1.0000,0.0105,0.0169,
0.0122,0.0024,0.005,0.0589,0.0105,1.0000,0.0187,
0.0001,0.0001,0.0068,0.0011,0.0169,0.0187,1.0000,

};

QVector<double> values;
for ( uint i = 0; i < sizeof(matrix) / sizeof(double); i++ )
values += matrix[i];

// const int numColumns = 4;
const int numColumns = 7;
setValueMatrix(values, numColumns);

//setInterval( Qt::XAxis,
// QwtInterval( -0.5, 3.5, QwtInterval::ExcludeMaximum ) );
setInterval( Qt::XAxis,
QwtInterval( 0.5, 7.5, QwtInterval::ExcludeMaximum ) );
// setInterval( Qt::YAxis,
// QwtInterval( -0.5, 3.5, QwtInterval::ExcludeMaximum ) );
setInterval( Qt::YAxis,
QwtInterval( 0.5, 7.5, QwtInterval::ExcludeMaximum ) );
//setInterval( Qt::ZAxis, QwtInterval(1.0, 6.0) );
setInterval( Qt::ZAxis, QwtInterval(0.0, 1.0) );
}
};

class ColorMap: public QwtLinearColorMap
{
public:
ColorMap():
QwtLinearColorMap(Qt::darkBlue, Qt::darkRed)
{
addColorStop(0.2, Qt::blue);
addColorStop(0.4, Qt::cyan);
addColorStop(0.6, Qt::yellow);
addColorStop(0.8, Qt::red);
/* addColorStop(0.1, Qt::blue);
addColorStop(0.2, Qt::blue);
addColorStop(0.3, Qt::blue);
addColorStop(0.4, Qt::cyan);
addColorStop(0.6, Qt::yellow);
addColorStop(0.8, Qt::red);*/
}
};

Plot::Plot(QWidget *parent):
QwtPlot(parent)
{
#if 0
QwtPlotGrid *grid = new QwtPlotGrid();
grid->setPen(QPen(Qt:otLine));
grid->attach(this);
#endif

d_spectrogram = new QwtPlotSpectrogram();
d_spectrogram->setRenderThreadCount(0); // use system specific thread count

d_spectrogram->setColorMap( new ColorMap() );

d_spectrogram->setData(new RasterData());
d_spectrogram->attach(this);

const QwtInterval zInterval = d_spectrogram->data()->interval( Qt::ZAxis );
// A color bar on the right axis
QwtScaleWidget *rightAxis = axisWidget(QwtPlot::yRight);
rightAxis->setColorBarEnabled(true);
rightAxis->setColorBarWidth(40);
rightAxis->setColorMap(zInterval, new ColorMap() );

setAxisScale(QwtPlot::yRight,zInterval.minValue(), zInterval.maxValue(),0.1 );
enableAxis(QwtPlot::yRight);

plotLayout()->setAlignCanvasToScales(true);

// setAxisScale(QwtPlot::xBottom, 0.0, 3.0);
setAxisScale(QwtPlot::xTop, 1.0, 7.0);
//setAxisMaxMinor(QwtPlot::xBottom, 0);
//setAxisMaxMinor(QwtPlot::xBottom, 0);
setAxisMaxMinor(QwtPlot::xTop, 0);
setAxisScale(QwtPlot::yLeft, 1.0, 7.0);
setAxisMaxMinor(QwtPlot::yLeft, 0);

// QwtPlotMagnifier *magnifier = new QwtPlotMagnifier( canvas() );
// magnifier->setAxisEnabled( QwtPlot::yRight, false);

QwtPlotPanner *panner = new QwtPlotPanner( canvas() );
panner->setAxisEnabled( QwtPlot::yRight, false);
}

void Plot::exportPlot()
{
QString fileName = "rasterview.pdf";

#ifndef QT_NO_FILEDIALOG
const QList<QByteArray> imageFormats =
QImageWriter::supportedImageFormats();

QStringList filter;
filter += "PDF Documents (*.pdf)";
#ifndef QWT_NO_SVG
filter += "SVG Documents (*.svg)";
#endif
filter += "Postscript Documents (*.ps)";

if ( imageFormats.size() > 0 )
{
QString imageFilter("Images (");
for ( int i = 0; i < imageFormats.size(); i++ )
{
if ( i > 0 )
imageFilter += " ";
imageFilter += "*.";
imageFilter += imageFormats[i];
}
imageFilter += ")";

filter += imageFilter;
}

fileName = QFileDialog::getSaveFileName(
this, "Export File Name", fileName,
filter.join(";;"), NULL, QFileDialog:ontConfirmOverwrite);
#endif
if ( !fileName.isEmpty() )
{
QwtPlotRenderer renderer;
renderer.renderDocument(this, fileName, QSizeF(300, 200), 85);
}
}

void Plot::setResampleMode(int mode)
{
RasterData *data = (RasterData *)d_spectrogram->data();
data->setResampleMode( (QwtMatrixRasterData::ResampleMode) mode);

replot();
}


Please let me know where i am wrong and how to plot this graph

[Uwe]

Beside, that the screenshot is so small, that I can hardly see the scales: is it what you want to have or what you get ? And if it is not what you want to have- what exactly is wrong with it ?

Uwe

[johnMick]

Hi Uwe,
The attached image is expected result and scale is (xTop :1 to 7
YLeft: 1 to 7 (from up to down).

In my actual out put i am getting y axis divison as 1 to 7(from down to up ) and output images(red squares) as diagonally right up to left down( which should be diagonally left up to left down).
Can u pls see the code what modification is required for same values as given in code?
Thanks in advance

[Uwe]

If all you want is to invert the y axis:

//setAxisScale(QwtPlot::yLeft, 1.0, 7.0);
setAxisScale(QwtPlot::yLeft, 7.0, 1.0);

//setAxisScale(QwtPlot::yLeft, 1.0, 7.0);
setAxisScale(QwtPlot::yLeft, 7.0, 1.0);

To copy to clipboard, switch view to plain text mode 

In case of using autoscaling this can be done with setting the QwtScaleEngine::Inverted attribute.

Uwe

[johnMick]

I also wanted that my red squares will start from 0.5 and end with 1.5 ? what values should i set in setInterval method?

[Uwe]

I also wanted that my red squares will start from 0.5 and end with 1.5 ?

That's what they do, but you are setting the scales, so that half of the first square is cut off.

I guess this is your code:

#if 0
    setAxisScale( QwtPlot::xTop, 1.0, 7.0 );
    setAxisScale( QwtPlot::yLeft, 7.0, 1.0 );
#else
    for ( int i = 0; i < QwtPlot::axisCnt; i++ )
        axisScaleEngine( i )->setAttribute( QwtScaleEngine::Floating, true );
    axisScaleEngine( yLeft )->setAttribute( QwtScaleEngine::Inverted, true );
#endif

#if 0
    setAxisScale( QwtPlot::xTop, 1.0, 7.0 );
    setAxisScale( QwtPlot::yLeft, 7.0, 1.0 );
#else
    for ( int i = 0; i < QwtPlot::axisCnt; i++ )
        axisScaleEngine( i )->setAttribute( QwtScaleEngine::Floating, true );
    axisScaleEngine( yLeft )->setAttribute( QwtScaleEngine::Inverted, true );
#endif

To copy to clipboard, switch view to plain text mode 

Uwe

[johnMick]

Hi,
I have one more doubt , in my output red image(color zone) is coming as rectangle but i want should be display as square
is it any way that i can set color zone as square?

[Uwe]

A spectrogram or any raster data object has no color zones, rectangles or squares !

I guess what you want to have is a plot with a fixed aspect ratio ( see qwt_plot_rescaler ).

Uwe