R: Rotate text independent of scaling (using mtext)?

Question

There are two ways to create rotated axis labels in R:

• text(srt = angle)

  • Advantage: Arbitrary angle possible (like 45°)
  • Disadvantage: y position changes with y scaling

• mtext(las = 1)

  • Advantage: y position fixed independent of y scaling
  • Disadvantages: Only discrete values possible (90° steps)

Is there a way to add rotated axis labels of whom the y position does not depend on the scaling of the y axis?

Answer 1

Thinking about the problem, I found a solution making use of the ylim parameter to the plot() function:

ylim = c(0, 0.5)
plot(...)
text(..., srt = 45, y = 0.2 * (ylim[2] - ylim[1]))

dynamically adjusts the position of the text according to the scaling of the y axis.