Imagine I have five concentrations of a species, then simulate a UV absorption spectrum for each concentration (five in total)(call it original spectrum). then , I add a constant value of 0.8 to all of these spectra, creating what I'll call an increased spectrum. When mean centering both the original and increased spectra, the resulting figures should be the same (and they are!). However, how should the figure look: Fig. 1 or Fig. 2?
What is the average absorption? What means "simulate a UV absorption spectrum?" I have never heard about "mean centering"? What is the goal of such manipulations with spectra?
Why would you add a baseline to the absorbance? Maybe I lack imagination, but I cannot see under which circumstances this could make sense in case of real samples/materials...
As far as I can see the difference between the two is that in the first, the average of the whole of each spectrum has been subtracted from the value of each wavelength of that spectrum, whereas in the second, the average of all spectra at a fixed wavelength has been subtracted from the value of each spectrum at that wavelength.
Therefore in the first, the baseline value at e.g. 400 nm is different for each, where as in the second it is zero for all.
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