#include <stdlib.h> #include <qapplication.h> #include <qpen.h> #include <qwt_plot.h> #include <qwt_plot_grid.h> #include <qwt_plot_marker.h> #include <qwt_interval_data.h> #include "histogram_item.h" int main(int argc, char **argv) { QApplication a(argc, argv); QwtPlot plot; plot.setCanvasBackground(QColor(Qt::white)); plot.setTitle("Histogram"); QwtPlotGrid *grid = new QwtPlotGrid; grid->enableXMin(true); grid->enableYMin(true); grid->setMajPen(QPen(Qt::black, 0, Qt::DotLine)); grid->setMinPen(QPen(Qt::gray, 0 , Qt::DotLine)); grid->attach(&plot); HistogramItem *histogram = new HistogramItem(); histogram->setColor(Qt::darkCyan); const int numValues = 20; QwtArray<QwtDoubleInterval> intervals(numValues); QwtArray<double> values(numValues); double pos = 0.0; for ( int i = 0; i < (int)intervals.size(); i++ ) { const int width = 5 + rand() % 15; const int value = rand() % 100; intervals[i] = QwtDoubleInterval(pos, pos + double(width)); values[i] = value; pos += width; } histogram->setData(QwtIntervalData(intervals, values)); histogram->attach(&plot); plot.setAxisScale(QwtPlot::yLeft, 0.0, 100.0); plot.setAxisScale(QwtPlot::xBottom, 0.0, pos); plot.replot(); #if QT_VERSION < 0x040000 a.setMainWidget(&plot); #endif plot.resize(600,400); plot.show(); return a.exec(); }