1. A system, comprising: a downhole formation fluid sampling tool; an optical spectrometer of the downhole formation fluid sampling tool, wherein the optical spectrometer is configured to measure an optical characteristic of a formation fluid flowing through the downhole formation fluid sampling tool over a plurality of wavelengths and configured to generate optical spectra data indicative of the optical characteristic, wherein the formation fluid comprises multiple components; and a processor configured to receive the optical spectra data generated by the optical spectrometer, to predict a parameter corresponding to one component of the multiple components of the formation fluid based on the optical spectra data including transforming the optical spectra data according to a set of mapping values, and to calculate a quantitative uncertainty in the predicted parameter based on the optical spectra data based on a set of covariance values corresponding to the set of mapping values or based on a set of covariance values corresponding to the obtained optical spectra data or both.