The extractionin the yellow panel works by comparing the text information of the PR(txt) wave, defined for the PMF input and the text wave selected as “x-axis” in the yellow panel. I.e., the name of the ions for HR-AMS of the PMF input is compared with that of the external data (and not the numeric value). Only intensities of the reference profile at variables with an exact text match with the PMF input are being kept. If reference profiles come back with only NaNs after the treatment of external data in the yellow panel, most likely the PR(txt) wave was wrongly defined.