How to find the angle of a line with respect to plot window

  This is a little hard to explain. I am not looking for the angle of the line with respect to the cartesian coordinates, I am looking for the angle with respect to the plot window itself.   For context, I am trying to use this angle to produce some text that has the same angle as the line   For Example:     plot([0:10], [0:10]) text( 0, 0, "----------------------some text", Rotation = 45) p = subplot(1,1,1); disp(p.Position(3:4))   disp(p.Position(3:4)) 0.7750 0.8150 See how the text angle doesn't match the line angle, and the plot itself is not a square i- I'd imagine some calculations are in order, and it would need the size of the window as an input.   ii- I also thought that ths cannot be that complex, surely there's a way to write text on the plot at an angle relative to the plot's coordiates, right?   If anyone has someinsight on (i) or (ii), that would be highly appriociated!