[Question] Can sec_axis be used to add more than one secondary axis?

[Parker Golliglee]

I am trying to plot data from USGS stream gages and would like to include discharge, temperature and turbidity over time. These all use different scales so I would like to add 2 additional y-axis. I have fooled around a little, and have successfully added a secondary axis, but I can not get a tertiary axis to graph as well. I would really like to do this in ggplot2 as I plan to animate this figure as a part of a presentation. Thank you in advance for your help.

[Oliver Lee]

You can just add a vertical line as the third axis: geom_vline()

For the number you need to scale it to be in line with the primary axis.

[Parker Golliglee]

unfortunately I was not able to get this solution to work, I would like the third axis to extend outside of the plot, beyond the first and have its own title and scale. I may just be unsure of how to do this with geom_vline(), but I was unable to add a line outside of my plot.

[Oliver Lee]

The likely solution is to extend your xlim and put the third vertical line inside the plot.

It can have its own scale as long as you adjust the number in respective data seiries.