Distribution of spectroscopic (left column) and photometric (right column) data, within our SOMs trained on the full spectroscopic compilation (top row) and the without-DEEP2 compilation (bottom row). The photometric data have similar structures (the missing bright-magnitude wedge can be used as a reference in each of these panels). Despite the different distribution of spectral and photometric data in the two SOMs, the representation statistics remain essentially unchanged: in both cases ∼5% of the photometric data occupy cells not containing spectra.