Hi to all! Some time ago I downloaded Qwt. All OK. Compiling OK. Installing OK.
A troubles with using in project was resolved successfully. But I need a histogram.
Well, there is an example present in source code. Good. Building... OK.
Trying to start examples one by one.
bode - segmentation fault
cpuplot - symbol lookup error: ./cpuplot: undefined symbol: _ZNK9QwtLegend4findEPK20QwtLegendItemManager ????
curvedemo1, curvedemo1 - segmentation fault
data_plot - segmentation fault :-/
dials - ok :-D
event_filter - ok :-)
histogram - segmentation fault :-/
radio - ok :-D
realtime - segmentation fault :-/
simple - segmentation fault :-/
sliders - ok :-D
spectrogram - segmentation fault >:-/
sysinfo - ok :-)

So, it`s a pity, but I can`t see most interesting examples. Well. I`m trying to write a histogram for my project. Step by step I`m trying to understand what`s wrong with example "histogram". As I understood there are no class like QwtHistogram. So, in example I have
Qt Code: 
  1. class HistogramItem: public QwtPlotItem
  2. {
  3. public:
  4.     explicit HistogramItem(const QString &title = QString::null);
  5.     explicit HistogramItem(const QwtText &title);
  6.     virtual ~HistogramItem();
  7.  
  8.     void setData(const QwtIntervalData &data);
  9.     const QwtIntervalData &data() const;
  10.  
  11.     void setColor(const QColor &);
  12.     QColor color() const;
  13.  
  14.     virtual QwtDoubleRect boundingRect() const;
  15.  
  16.     virtual int rtti() const;
  17.  
  18.     virtual void draw(QPainter *, const QwtScaleMap &xMap, 
  19.         const QwtScaleMap &yMap, const QRect &) const;
  20.  
  21.     void setBaseline(double reference);
  22.     double baseline() const;
  23.  
  24.     enum HistogramAttribute
  25.     {
  26.         Auto = 0,
  27.         Xfy = 1
  28.     };
  29.  
  30.     void setHistogramAttribute(HistogramAttribute, bool on = true);
  31.     bool testHistogramAttribute(HistogramAttribute) const;
  32.  
  33. protected:
  34.     virtual void drawBar(QPainter *,
  35.         Qt::Orientation o, const QRect &) const;
  36.  
  37. private:
  38.     void init();
  39.  
  40.     class PrivateData;
  41.     PrivateData *d_data;
  42. };
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I wrote a test as copy of example:
Qt Code: 
  1. #include <stdlib.h>
  2. #include <qapplication.h>
  3. #include <qpen.h>
  4. #include <qwt_plot.h>
  5. #include <qwt_plot_grid.h>
  6. #include <qwt_plot_marker.h>
  7. #include <qwt_interval_data.h>
  8. #include "histogram_item.h"
  9.  
  10. int main(int argc, char **argv)
  11. {
  12.     QApplication a(argc, argv);
  13.  
  14.     QwtPlot* plot = new QwtPlot(0);
  15.     plot->setCanvasBackground(QColor(Qt::white));
  16.     plot->setTitle("Histogram");
  17.  
  18.     QwtPlotGrid *grid = new QwtPlotGrid;
  19.     grid->enableXMin(true);
  20.     grid->enableYMin(true);
  21.     grid->setMajPen(QPen(Qt::black, 0, Qt::DotLine));
  22.     grid->setMinPen(QPen(Qt::gray, 0 , Qt::DotLine));
  23.     grid->attach(plot);
  24.  
  25.     HistogramItem *histogram = new HistogramItem();
  26.     histogram->setColor(Qt::darkCyan);
  27.  
  28.     const int numValues = 20;
  29.  
  30.     QwtArray<QwtDoubleInterval> intervals(numValues);
  31.     QwtArray<double> values(numValues);
  32.  
  33.     double pos = 0.0;
  34.     for ( int i = 0; i < (int)intervals.size(); i++ )
  35.     {
  36.         const int width = 5 + rand() % 15;
  37.         const int value = rand() % 100;
  38.  
  39.         intervals[i] = QwtDoubleInterval(pos, pos + double(width));
  40.         values[i] = value; 
  41.  
  42.         pos += width;
  43.     }
  44.  
  45.     histogram->setData(QwtIntervalData(intervals, values));
  46.     histogram->attach(plot);
  47.  
  48.     plot->setAxisScale(QwtPlot::yLeft, 0.0, 100.0);
  49.     plot->setAxisScale(QwtPlot::xBottom, 0.0, pos);
  50.     plot->replot();
  51.  
  52. #if QT_VERSION < 0x040000
  53.     a.setMainWidget(&plot);
  54. #endif
  55.  
  56.     plot->resize(600,400);
  57.     plot->show();
  58.  
  59.     return a.exec(); 
  60. }
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and got segmentation fault in return a.exec();

Can you help me? Were is problem may be? May be another way present to make histogram?
Thanks a lot everyone!