  We show how the range of application of the principal component
analysis-based inversion method of Paletou et al. (2015) can be extended to
late-type stars data. Besides being an extension of its original application
domain, for FGK stars, we also used synthetic spectra for our learning
database. We discuss our results on effective temperatures against previous
evaluations made available from Vizier and Simbad services at CDS.
