In the loop you use to read your file.

@suslucoder said in Assign specific value to axis:

I want to assign axis Y the 3rd column. How can i do it?

The axis does not know anything about that file and columns inside it. You simply need to read your file and put data from that third column as data for Y axis. See https://doc.qt.io/qt-5/qxyseries.html
If you read documentation https://doc.qt.io/qt-5/qxyseries.html#append you will see that you have to provide X AND Y...

Thanks for the support guys. I tried making a transparent QPixmap image using Qt::transparent fill for the axis and overlaying it onto my other QPixmap, however it didn't work properly. So I ended up just drawing directly onto the image itself. Not the most efficient method but it seems to work...

@houmingc You took that example straight from the documentation page for Rotation, which shows a picture of exactly what will happen. What more do you need? "Default angle" makes no sense. If you don't specify one there will be no rotation. It rotates around the origin along the axis. If you still don't understand, make a quick example and play around with it.