PDS with sigmoid weighting for the mixed-model likelihood approach for a RGB simulation. The raw spectrum is shown in grey with a binned version overplotted in black. The opacity of the binned PDS is set by the value of the sigmoid weight, indicated by the red profile gradually decreasing from 1 towards 0, as is indicated by the right-hand axis. The mean of the constant χ² likelihood, L₂, is indicated by the horizontal dashed orange line. The ν_max of the simulation is indicated by the vertical dashed black line.