I am trying to create a plot for my stable isotope data from sequential dentine sampling which provides deltaN15 and deltaC13 data as well as age assignments. I would like to have the x-axis be the age of the sample (i.e. 8 years old – 17 years old) while one y-axis would show the dN15 and the other the dC13 values. It would be two separate lines for each isotope and I know this can be done (I’ve seen it in papers). I know that in many cases having multiple y-axes is not preferred but this is an important indicator of health and famine when dealing with sequential dentine data.

I am trying to create a plot for my stable isotope data from sequential dentine sampling which provides deltaN15 and deltaC13 data as well as age assignments. I would like to have the x-axis be the age of the sample (i.e. 8 years old – 17 years old) while one y-axis would show the dN15 and the other the dC13 values. It would be two seperate lines for each isotope and I know this can be done (I’ve seen it in papers). I know that in many cases having multiple y-axes is not preferred but this is an important indicator of health and famine when dealing with sequential dentine data.

I have a graph here with Wavenumber as the primary x-axis. I have another column in my data table called Wavelength, that is a direct conversion from every data point in the Wavenumber column. Is there a way to put the Wavelength column on the top of the graph to have a secondary x-axis? Both Wavenumber and Wavelength will have the same amount of variables.