how to set the y-axis width?

[johno]

Hello,

i am playing with Qwt. Thanks for the great library! I have written an application with one or more plotters. In the first one i will draw a Chart of an financial market. In the plotter below i will draw as example an indicator. Please see the screenshot.
Clipboard 1.jpg

How can i set the width of the Y-axis on the right side of the plotter below?

I would have the same width as the plotter above (with the candle-sticks). I tried so many things with plotter->axisWidget(QwtPlot::yRight)->resize() etc. but nothing work. Thanks for any suggestions!

Best regards,
johno


EDIT: The vertical line is a QwtPlotMarker. I set the position with: plottMarker->setValue(chartPlotter->invTransform(QwtPlot::xBottom, pos.x()), 0); from the plotter above (with the signal: moved(QPoint) from QwtPlotPicker). It works, but it looks crazy because of the different width of the y-axis.

[Uwe]

Have a look at the plotmatrix example.

Uwe

[johno]

Thank you Uwe, the plotmatrix example helps me!

My solution:

void MainWindow::updatePlotters(double lowerBound, double upperBound) {
	QwtScaleWidget *scaleWidget;
	QwtScaleDraw *scaleDraw;
	double maxExtent = 0;
	double extent = 0;
 
	for(int i = 0; i < currentTrader->plotters.size(); i++) {
		currentTrader->plotters.at(i)->setAxisScale(QwtPlot::xBottom, lowerBound, upperBound);
		scaleWidget = currentTrader->plotters.at(i)->axisWidget(QwtPlot::yRight);
		scaleDraw = scaleWidget->scaleDraw();
		extent = scaleDraw->extent(scaleWidget->font());
		if(extent > maxExtent) maxExtent = extent;
		scaleDraw->setMinimumExtent(maxExtent);
		currentTrader->plotters.at(i)->updateLayout();
		currentTrader->plotters.at(i)->replot();
	}
}

void MainWindow::updatePlotters(double lowerBound, double upperBound) {
	QwtScaleWidget *scaleWidget;
	QwtScaleDraw *scaleDraw;
	double maxExtent = 0;
	double extent = 0;

	for(int i = 0; i < currentTrader->plotters.size(); i++) {
		currentTrader->plotters.at(i)->setAxisScale(QwtPlot::xBottom, lowerBound, upperBound);
		scaleWidget = currentTrader->plotters.at(i)->axisWidget(QwtPlot::yRight);
		scaleDraw = scaleWidget->scaleDraw();
		extent = scaleDraw->extent(scaleWidget->font());
		if(extent > maxExtent) maxExtent = extent;
		scaleDraw->setMinimumExtent(maxExtent);
		currentTrader->plotters.at(i)->updateLayout();
		currentTrader->plotters.at(i)->replot();
	}
}

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Added after 16 minutes:

But a small problem still remains. I thought this would go away if the plotter's have the same drawing area/size. It is about the position of the QwtPlotMarker in the lower plotter (indicator-plotter). I set his position with the position of the QwtPlotPicker from the chart-plotter (the main plotter above).

plotMarker->setValue(chartPlotter->invTransform(QwtPlot::xBottom, pos.x()), 0);

plotMarker->setValue(chartPlotter->invTransform(QwtPlot::xBottom, pos.x()), 0);

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It is almost accurate, but on the right and left side it differs a little bit. In the middle it is ok. Any idea? I use QwtPlotMagnifier to zoom in the chart and give the plotter->axisScaleDiv(QwtPlot::xBottom).lowerBound() and upperBound to the other plotters. So far everything works well, expect the position of the QwtPlotMarker in the second (indicator-chart). But i think this has nothing to do with the zoom functionality.

Any idea how I can fix / optimize this? Thanks a lot!

Best regards johno

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Added after 20 minutes:

better images:

PlotMarker_04.jpg
PlotMarker_05.jpg
PlotMarker_06.jpg

[johno]

for your information: This problem is now sloved too! I have to set on all plotters: plotter->plotLayout()->setAlignCanvasToScales(false);

Thanks a lot! Great library!!