Comparison of the Hα line profiles computed by our code (grey line) with the observation of SDSS J093653.84+533126.8. The parameters are: i= 8°, n1= 2.1π, n2= 3.0, n3= 6°, γ0= 117°, the disc zone is from Rin= 250rg to Rout= 1000rg for a retrograde disc.