Strange extra line in my plotting, help please

[Uwe]

You need to understand the meaning of the different layout options - no code.

Uwe

[cooper]

thanks Uwe, i will read the qwt layout class again.

[cooper]

Hi Uwe,

I have tried the plotLayout()->setAlignCanvasToScales. Here is my code:

ui->qwtPlot->plotLayout()->setAlignCanvasToScales(false);
ui->qwtPlot->plotLayout()->setCanvasMargin(50, -1);

ui->qwtPlot->plotLayout()->setAlignCanvasToScales(false);
ui->qwtPlot->plotLayout()->setCanvasMargin(50, -1);

To copy to clipboard, switch view to plain text mode 

I got this:


the length of the scale backbone has been shorted.
What i really want is to make the scale backbone skinner. The reason is that the screen what i am running my application is only 4.3". I need get more space to display the chart. Therefore, i want to save some scale backbone space (even a little bit) to my chart. I wish the scale backbone will be looks like:



Is that possible to achieve? Thanks for your help.

[Uwe]

Maybe plot->axisWidget(...)->setMargin(0); is what you want. You can also save some pixels by reducing the spacing and you could disable the frame of the canvas. Another idea is to disable the left axis completely and to insert a QwtPlotScaleItem on the canvas instead.

Uwe

[cooper]

Thanks Uwe,

after i setup "setMargin(0)" and disable the frame of canvas, I got saved some pixels in my plotting screen.

Thank for your help