Demo showing Qwt (multiaxis branch) with multiple Y-Axis labels

qwt_multi-yaxis.cpp

/**
 * Demo showing Qwt (multiaxis branch) with multiple Y-Axis labels
 **/

#include <QApplication>
#include <qwt_plot.h>
#include <qwt_plot_curve.h>
#include <qwt_plot_grid.h>
#include <qwt_symbol.h>
#include <qwt_legend.h>
#include <qwt_point_data.h>
#include <qwt_plot_canvas.h>
#include <qwt_axis_id.h>

#include <cmath>

int main(int argc, char *argv[])
{
QApplication a(argc, argv);

QwtAxisId axisY1(0,0);
QwtAxisId axisY2(0,1);
QwtAxisId axisY3(0,2);

QwtPlot plot;
plot.setTitle( "Plot Demo" );
plot.setCanvasBackground( Qt::white );
plot.setAxesCount(0, 3);

plot.setAxisAutoScale(axisY1,true);
plot.setAxisAutoScale(axisY2,true);
plot.setAxisAutoScale(axisY3,true);

// Enable differents combinations,
// Qwt seems to allocate the widths correctly.
//plot.setAxisVisible(axisY1,false);
//plot.setAxisVisible(axisY2,false);
plot.setAxisVisible(axisY3,false);

plot.insertLegend( new QwtLegend() );

QwtPlotCanvas *canvas = new QwtPlotCanvas();
canvas->setLineWidth( 1 );
canvas->setFrameStyle( QFrame::Box | QFrame::Plain );

QPalette canvasPalette( Qt::white );
canvasPalette.setColor( QPalette::Foreground, QColor( 131, 131, 131 ) );
canvas->setPalette( canvasPalette );

plot.setCanvas(canvas);

QVector<double> listX;
QVector<double> list1y, list2y;

for (int var = 0.1; var < 6.28; ++var) {
	listX.push_back(var);
	list1y.push_back(std::sin(var));
	list2y.push_back(2*cos(var));
}

QwtPointArrayData data1(listX,list1y);
QwtPointArrayData data2(listX,list2y);

QwtPlotCurve *curve1 = new QwtPlotCurve();
QwtPlotCurve *curve2 = new QwtPlotCurve();

curve1->setTitle( "Curve Sin(x)" );
curve1->setPen( Qt::blue, 4 ),
curve1->setRenderHint( QwtPlotItem::RenderAntialiased, true );
curve1->setSamples(&data1);

curve2->setTitle( "Curve 2*cos(x)" );
curve2->setPen( Qt::red, 4 ),
curve2->setRenderHint( QwtPlotItem::RenderAntialiased, true );
curve2->setSamples(&data2);

curve1->setYAxis(axisY1);
curve2->setYAxis(axisY2);

curve1->attach( &plot );
curve2->attach( &plot );

plot.replot();
plot.resize( 600, 400 );
plot.show();

return a.exec();
}
me@precision:~/Documents/multiaxis$ cat main.cpp
// Demo showing Qwt (multiaxis branch)
// with multiple Y-Axis labels

#include <QApplication>
#include <qwt_plot.h>
#include <qwt_plot_curve.h>
#include <qwt_plot_grid.h>
#include <qwt_symbol.h>
#include <qwt_legend.h>
#include <qwt_point_data.h>
#include <qwt_plot_canvas.h>
#include <qwt_axis_id.h>

#include <cmath>

int main(int argc, char *argv[])
{
	QApplication a(argc, argv);
	
	QwtAxisId axisY1(0,0);
	QwtAxisId axisY2(0,1);
	QwtAxisId axisY3(0,2);
	
	QwtPlot plot;
	plot.setTitle( "Plot Demo" );
	plot.setCanvasBackground( Qt::white );
	plot.setAxesCount(0, 3);
	
	plot.setAxisAutoScale(axisY1,true);
	plot.setAxisAutoScale(axisY2,true);
	plot.setAxisAutoScale(axisY3,true);
	
	// Enable differents combinations,
	// Qwt seems to allocate the widths correctly.
	//plot.setAxisVisible(axisY1,false);
	//plot.setAxisVisible(axisY2,false);
	plot.setAxisVisible(axisY3,false);
	
	plot.insertLegend( new QwtLegend() );
	
	QwtPlotCanvas *canvas = new QwtPlotCanvas();
	canvas->setLineWidth( 1 );
	canvas->setFrameStyle( QFrame::Box | QFrame::Plain );
	
	QPalette canvasPalette( Qt::white );
	canvasPalette.setColor( QPalette::Foreground, QColor( 131, 131, 131 ) );
	canvas->setPalette( canvasPalette );
	
	plot.setCanvas(canvas);
	
	QVector<double> listX;
	QVector<double> list1y, list2y;
	
	for (int var = 0.1; var < 6.28; ++var) {
		listX.push_back(var);
		list1y.push_back(std::sin(var));
		list2y.push_back(2*cos(var));
	}
	
	QwtPointArrayData data1(listX,list1y);
	QwtPointArrayData data2(listX,list2y);
	
	QwtPlotCurve *curve1 = new QwtPlotCurve();
	QwtPlotCurve *curve2 = new QwtPlotCurve();
	
	curve1->setTitle( "Curve Sin(x)" );
	curve1->setPen( Qt::blue, 4 ),
	curve1->setRenderHint( QwtPlotItem::RenderAntialiased, true );
	curve1->setSamples(&data1);
	
	curve2->setTitle( "Curve 2*cos(x)" );
	curve2->setPen( Qt::red, 4 ),
	curve2->setRenderHint( QwtPlotItem::RenderAntialiased, true );
	curve2->setSamples(&data2);
	
	curve1->setYAxis(axisY1);
	curve2->setYAxis(axisY2);
	
	curve1->attach( &plot );
	curve2->attach( &plot );
	
	plot.replot();
	plot.resize( 600, 400 );
	plot.show();
	
	return a.exec();
}

hey @gastmaier

thank you for showcasing this approach, Can i ask you some questions if possible?