Visual diagnostic of the quality of the fit on the lines used for the inversion of OMC-1 for four pixels. The blue points are the actual observation with a 1σ error for the multiplicative noise. The orange stars are the prediction of the Meudon PDR code based on the MMSE. The orange violin plots show the predictions of the Meudon PDR code on samples of the posterior distribution. The green violin plots show the posterior predictive distribution by including addition and multiplicative noises.