Fitting parameters and their errors for the case ℓ = 492 (k_pix = 21). Each panel has three parts. In the upper part of each panel, squares indicate the input parameters, . The asterisks indicate the fitting results obtained by the updated code, namely, the mean of Monte-Carlo samples, . In the middle part of each panel, the deviation of the mean fitting results from the input, , are illustrated by the circles and the expected scatter of the mean computed from the square root of variance σ^scat of the 500 Monte Carlo samples divided by the square root of the sample number, N_sample (here it is 500) are shown as the error bars. The dashed horizontal lines are at δq = 0. In the lower part of each panel the scatter of the 500 samples, σ^scat and the scaled error estimated by the updated code, σ^code, are depicted by the thick gray lines and the thin lines with short horizontal bars on the edge. Errors estimated by the updated code are scaled by σ(α = 1.5, k_pix, n_pix) = 0.569 as described in Appendix B.2. The error bars on the middle panel of δq_1, n are tiny at this scale; the underestimation is relatively large. However, the errors of δq_1, n are and, therefore, available from σ^scat in the lower panel and N_sample = 500; they are ∼0.02 at most.