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#include <stdlib.h>
#ifdef QWT_QTOPIA
#include <qpe/qpeapplication.h>
#endif
#include <qapplication.h>
#include <qwt_plot.h>
#include <qwt_plot_canvas.h>
#include <qwt_scale.h>
#include <qwt_scldraw.h>
#include <qwt_math.h>
const int PLOT_SIZE = 201; // 0 to 200
//-----------------------------------------------------------------
// data_plot.cpp
//
// This example shows how to display time-varying data
// using QwtPlot.
//
//-----------------------------------------------------------------
class DataPlot : public QwtPlot
{
public:
DataPlot();
protected:
virtual void timerEvent(QTimerEvent *e);
private:
void alignScales();
double x[PLOT_SIZE], y[PLOT_SIZE], z[PLOT_SIZE];
};
//
// Initialize main window
//
DataPlot::DataPlot()
{
alignScales();
// Initialize data
for (int i = 0; i< PLOT_SIZE; i++)
{
x[i] = 0.5 * double(i); // time axis
y[i] = 0;
z[i] = 0;
}
// Assign a title
setTitle("Another Simple QwtPlot Demonstration");
setAutoLegend(TRUE);
// Insert new curves
long cRight = insertCurve("Data Moving Right");
long cLeft = insertCurve("Data Moving Left");
// Set curve styles
setCurvePen(cRight, QPen(Qt::red));
setCurvePen(cLeft, QPen(Qt::blue));
// Attach (don't copy) data. Both curves use the same x array.
setCurveRawData(cRight, x, y, PLOT_SIZE);
setCurveRawData(cLeft, x, z, PLOT_SIZE);
// Insert zero line at y = 0
long mY = insertLineMarker("", QwtPlot::yLeft);
setMarkerYPos(mY, 0.0);
// Set axis titles
setAxisTitle(QwtPlot::xBottom, "Time/seconds");
setAxisTitle(QwtPlot::yLeft, "Values");
// Generate timer event every 50ms
(void)startTimer(50);
}
//
// Set a plain canvas frame and align the scales to it
//
void DataPlot::alignScales()
{
// The code below shows how to align the scales to
// the canvas frame, but is also a good example demonstrating
// why the spreaded API needs polishing.
canvas()->setFrameStyle(QFrame::Box | QFrame::Plain );
canvas()->setLineWidth(1);
for ( int i = 0; i < QwtPlot::axisCnt; i++ )
{
QwtScale *scale = (QwtScale *)axis(i);
if ( scale )
scale->setBaselineDist(0);
QwtScaleDraw *scaleDraw = (QwtScaleDraw *)axisScaleDraw(i);
if ( scaleDraw )
{
scaleDraw->setOptions(
scaleDraw->options() & ~QwtScaleDraw::Backbone);
}
}
}
//
// Generate new values every 500ms.
//
void DataPlot::timerEvent(QTimerEvent *)
{
static double phase = 0.0;
if (phase > (M_PI - 0.0001)) phase = 0;
// y moves from left to right:
// Shift y array right and assign new value to y[0].
qwtShiftArray(y, PLOT_SIZE, 1);
y[0] = sin(phase) * (-1.0 + 2.0 * double(rand()) / double(RAND_MAX));
// z moves from right to left:
// Shift z array left and assign new value to z[n-1].
qwtShiftArray(z, PLOT_SIZE, -1);
z[PLOT_SIZE - 1] = 0.8 - (2.0 * phase/M_PI) + 0.4 *
double(rand()) / double(RAND_MAX);
// update the display
replot();
phase += M_PI * 0.02;
}
int main(int argc, char **argv)
{
#ifdef QWT_QTOPIA
QPEApplication a(argc, argv);
#else
QApplication a(argc, argv);
#endif
DataPlot plot;
a.setMainWidget(&plot);
plot.resize(500,300);
plot.show();
return a.exec();
}
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