Variations of the normalized discrepancy function for the Stokes QU profiles, , as a function of inclination angle i and azimuth angle Θ. The innermost unmarked contour plotted with the thick black line corresponds to the five-sigma confidence level of the fit. The other contours marked with 1.01, 1.05, and 1.10 correspond to an increase of 1%, 5%, and 10% of the discrepancy function from its minimum value.