Distribution of the photo-zz_p as a function of the spectro-zz_s. Top left panel: photo-z from the FastPZ method (see Sect. 3.1.2); top right panel: with the BDT 90% cut; bottom left panel: with the BDT 80% cut. The colour scale for the galaxy density is logarithmic. Bottom right panel: statistical properties of e_z = (z_s − z_p)/(1 + z_p) as a function of z_p with (top panel) the interquartile range IQR of e_z, (middle panel) fraction of outliers f_out, defined by |e_z|> 0.15, (bottom panel) bias b, defined as the median of e_z. Green lines show the values obtained with the photo-z’s without any quality cut while the pink (purple) lines show the results with the photo-z satisfying BDT 90% (BDT 80%) cut. The dashed black lines correspond to the LSST requirements (plus the goal value in the IQR case).