Comparisons between the distributions of different properties in the test sample and their KDE (solid line). From top to bottom: galactic latitude (b), X-ray to r-band flux ratio (log₁₀(F_X/F_r)), hardness ratio between soft and medium X-ray bands (HR1), and logarithm of the max over mean flux ratio in the most variable XRT band (logFratioSnap). The y axis is in arbitrary units. In the first and third panels, only three classes are shown, to ease the graph readability. The b distribution of XRBs resembles a very sharp peak at 0° and some tails that look like the CV distribution. The HR1 distribution of CVs shows a good agreement with the KDE, which is shown in Fig. 2.