Hello,

I would like to adapt the colormap in regard to the max and min values of intensity ( in a spectrogram). How can it be done?

here the colormap is set:

Qt Code: 
  1. QwtValueList contourLevels;
  2.     for ( double level = 0.5; level < 10.0; level += 1.0 )
  3.         contourLevels += level;
  4.     d_spectrogram->setContourLevels(contourLevels);
  5.  
  6.     // A color bar on the right axis
  7.     QwtScaleWidget *rightAxis = axisWidget(QwtPlot::yRight);
  8.     rightAxis->setTitle("Intensity");
  9.     rightAxis->setColorBarEnabled(true);
  10.     rightAxis->setColorMap(d_spectrogram->data().range(), d_spectrogram->colorMap());
  11.  
  12.     setAxisScale(QwtPlot::yRight,
  13.         d_spectrogram->data().range().minValue(),
  14.         d_spectrogram->data().range().maxValue() );
  15.     enableAxis(QwtPlot::yRight);
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and my QwtData is:

Qt Code: 
  1. typedef double (*benchFunc)(double, double);	// definition of function pointer for benchmark function
  2.  
  3. class SpectrogramData: public QwtRasterData
  4. {
  5. public:
  6.     SpectrogramData(benchFunc b, double rang1[2],  double rang2[2]):
  7.         QwtRasterData(QwtDoubleRect(rang1[0], rang2[0], rang1[1]- rang1[0], rang2[1]- rang2[0]))
  8.     {
  9.     	MybenchFunc = b;
  10.     	rangeX1[0] = rang1[0];	rangeX1[1] = rang1[1];
  11.     	rangeX2[0] = rang1[0];	rangeX2[1] = rang2[1];
  12.     }
  13.  
  14.     virtual QwtRasterData *copy() const
  15.     {
  16.         return new SpectrogramData(*this);
  17.     }
  18.  
  19.     virtual QwtDoubleInterval range() const
  20.     {
  21.         return QwtDoubleInterval(-5.0, 5.0);
  22.     }
  23.  
  24.     virtual double value(double x, double y) const
  25.     {
  26.  
  27.     	const double result = MybenchFunc(x,y);
  28.         return result;
  29.     }
  30.  
  31. private:
  32.  
  33. 	benchFunc MybenchFunc;	// function pointer for benchmark function
  34. 	double rangeX1[2];
  35. 	double rangeX2[2];
  36. };
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At the moment the range is set to (-5, 5), but it is fix. I want to make it dynamical.

Thanks for help.

best regards,

Vitali