SED fit error regions too small to be right

[ranieremenezes]

Hello,

The fit uncertainty region saved in the TARGET_NAME_sed.fits by the GTAnalysis function sed() is often unreasonable small, as shown in the figure below (it looks like a single solid line, but there are three lines in total, i.e. one line for the fit, and two delimiting the uncertainty region).

This analysis was done for BL Lac with the following configuration:

emin : 100.0
emax : 200000.0
zmax : 90
evclass : 128
evtype : 3
ra: 330.68038041666665
dec: 42.277771944444446
tmin: 239557417
tmax: 245691781

The same issue frequently happens with other data sets and spectral models, even if the fit quality returned by GTAnalysis.fit() is 3 (as is the case for the plot shown above).