Responding to Frederik's posting at
http://lists.wfu.edu/pipermail/gretl-users/2017-December/012814.html
"Sometimes the candlebars pretend values which do not exist. I.e.,
if the IQR *1.5 data does not exist (which can happen - it happens
to me), the boxplot gives a false impression."
Please try a current gretl snapshot. This was a known issue but we
believe it's now fixed. In the current Changelog we have:
Boxplots: fix for incorrect extent of "whiskers" in some cases
Allin