Loads spectra and classification from database Makes up a 'data' structure with - X: data matrix (rows are spectra, columns are wavenumbers) - classes: classification index (0, 1, 2 and so on), one for each row in data. - idspectrum_s: a column vector containing the same number of row as DATA. Its elements are the spectrum id corresponding to each row in DATA - no_wavenumbers: matches number of columns in data.X but comes from a different source - class_labels: legends for each class - idjudge_ref: db:judge.id