Test_qwt::Test_qwt(QWidget *parent, Qt::WFlags flags)
    : QMainWindow(parent, flags)
{
    ui.setupUi(this);

    double X1[20], Y1[20],X2[20], Y2[20];
    int Size,i;

    Size = 20;

    for (i=0;i<20;i++){
        X1[i] = rand()/32;
        Y1[i] = rand()/32;
        X2[i] = rand()/32;
        Y2[i] = rand()/32;
    }

    QwtPlot *myPlot = new QwtPlot(tr("Test"), this);

    // add curves
    QwtPlotCurve *curve1 = new QwtPlotCurve("Curve 1");
    QwtPlotCurve *curve2 = new QwtPlotCurve("Curve 2");

    curve1->setPen(QPen(Qt::red));
            curve2->setPen(QPen(Qt::blue));

    // copy the data into the curves
    curve1->setData(X1,Y1,Size);
    curve2->setData(X2,Y2,Size);

    curve1->attach(myPlot);
    curve2->attach(myPlot);

    // finally, refresh the plot
    myPlot->replot();

}

QwtPlot *myPlot = new QwtPlot(tr("Test"), this);