i don't know how to debug in console mode but i tried with qt creator .
when i run debug mode ,it still running with no information given ,debugger don't run until the first break point , it's written dbg running .

plot.h :
Qt Code: 
  1. #include <QtGui>
  2. #include <qwt_plot.h>
  3. #include <qwt_plot_curve.h>
  4. #include <qwt_plot_marker.h>
  5. #include <qwt_plot_curve.h>
  6. #include <qwt_legend.h>
  7. #include <qwt_series_data.h>
  8. #include <qwt_text.h>
  9. #include <math.h>
  10.  
  11.  
  12. class Plot : public QwtPlot
  13. {
  14. Q_OBJECT
  15.     public:
  16.       Plot();
  17.       ~Plot();
  18.       void pointByPoint();
  19.  
  20.     private :
  21.        QwtPlotCurve *curve;
  22.        int currentPointPosition;
  23.        QTimer *timer;
  24.        double *x;
  25.        double *y;
  26.  
  27.     public slots:
  28.         void onTimeout();
  29. };
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plot.cpp :
Qt Code: 
  1. #include "plot.h"
  2.  
  3. Plot::Plot()
  4. {
  5.     x=new double[100];
  6.     y=new double[100];
  7.  
  8.     for(int i=0;i<100;i++){
  9.         x[i]=i;
  10.         y[i]=i*i;
  11.     }
  12.  
  13.    currentPointPosition=1;
  14.  
  15.    setTitle("Vitesse et angle de braquage en fonction du temps");
  16.    insertLegend(new QwtLegend(), QwtPlot::RightLegend);
  17.  
  18.    // Set axes
  19.    setAxisTitle(xBottom, "Temps");
  20.    setAxisScale(xBottom, 0.0, 100);
  21.  
  22.    setAxisTitle(yLeft, "");
  23.    setAxisScale(yLeft, 0.0, 100);
  24.  
  25.    // add curves
  26.    curve = new QwtPlotCurve("Vitesse");
  27.    curve->setPen(QPen(Qt::green));
  28.    curve->attach(this);
  29.    curve->setData(x, y, currentPointPosition);
  30.  
  31.      //  ...a horizontal line ...
  33.     mY->setLabel(QString::fromLatin1("t ( ms )"));
  34.     mY->setLabelAlignment(Qt::AlignRight|Qt::AlignTop);
  35.     mY->setLineStyle(QwtPlotMarker::HLine);
  36.     mY->attach(this);
  37.  
  38.     //  ...a vertical line ...
  40.     mX->setLabel(QString::fromLatin1("V ( m/s ) ,Ang ( rad/s )"));
  41.     mX->setLabelAlignment(Qt::AlignRight|Qt::AlignTop);
  42.     mX->setLineStyle(QwtPlotMarker::VLine);
  43.     mX->attach(this);
  44.  
  45.    timer = new QTimer();
  46.    connect(timer, SIGNAL(timeout()), this, SLOT(onTimeout()));
  47. }
  48.  
  49.  
  50. void Plot::onTimeout(){             //each timeout data will
  51.   currentPointPosition++;           // be added to the curve
  52.   if(currentPointPosition>100) currentPointPosition = 1;
  53.   curve->setData(x, y, currentPointPosition);
  54. }
  55.  
  56.  
  57. void Plot::pointByPoint(){ //calling this method provoque painting curve "slowly"
  58.     for(int i=0;i<200;i++){
  59.         timer->start(500);
  60.     }
  61. }
  62.  
  63. Plot::~Plot(){
  64.     delete x;
  65.     delete y;
  66. }
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main.cpp
Qt Code: 
  1. #include "plot.h"
  2.  
  3. int main(int argc, char **argv)
  4. {
  5.     QApplication a(argc, argv);
  6.  
  7.     Plot *myPlot = new Plot();
  8.     myPlot->autoRefresh();
  9.     myPlot->resize(600,400);
  10.     myPlot->show();
  11.  
  12.     myPlot->pointByPoint();
  13.  
  14.     return a.exec();
  15. }
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.pro :
Qt Code: 
  1. TEMPLATE = app
  2. TARGET = 
  3. DEPENDPATH += .
  4. INCLUDEPATH += C:\svn\qwt\qwt\src
  5. LIBS += C:\svn\qwt\qwt\lib\qwtd5.dll
  6. CONFIG += debug
  7.  
  8. # Input
  9. SOURCES += main.cpp \
  10.     plot.cpp
  11. HEADERS += plot.h
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i made as comment Q_OBJECT and my slot and it works ,i checked debugger too,it's ok with it under Qtcreator .