on the intrinsic FDFs rather than the observed FDFs to investigate how much information about the parameters the intrinsic FDFs have. It is necessary to interpret intrinsic FDFs, since it is impossible to obtain some information from observed FDFs if the information is not available from intrinsic FDFs.

Then, as simple measures to characterize the global shape, we calculated the probability distribution functions of the standard deviation, skewness and kurtosis of the FDFs and compared them for different models. We found that the presence of vertical magnetic fields and large scale-height of cosmic-ray electrons make the standard deviation relatively large so it can be a useful indicator of them. However, it should be noted that the effect of vertical fields would become smaller when we consider spiral galaxies with inclination. Contrastingly, differences in skewness and kurtosis are not so significant. Obviously, we need more sophisticated measures for the characterization of FDFs and we will pursue it in near future.

In the current study, the calculation of the FDF is limited to a relatively small region with 500 pc $\times$ 500 pc. At this scale, magnetic fields perpendicular to the LOS are dominated by global coherent fields rather than turbulent fields. 