Obscuration PDF definition. (Top) distribution of the SDSS sources classified as Type 1 and Type 2 AGN as a function of W2/W1 magnitudes. (Bottom) Obscuration PDF derived from the left figure and Eq. B.1 from a sigmoid fit to the points. The dashed gray line represents the cut threshold which defines whether an AGN is of Type 1 or 2. It was chosen by doing a grid search over Obscuration PDF values and choosing the value giving the best F1-score.