It looks like still in NetLogo 7 the “Auto scale x-axis?” does not work for histograms, so it is very easy to produce histograms that are misleading because they do not display values outside the x axis range that the user must specify in the graph widget (or via set-plot-x-range).
I wish auto scaling would work for histogram X axes, but if that is not possible then I really wish there was a way for NetLogo to warn the user when the histogram primitive does not plot the full range of results because some values are outside the X axis range. It is very easy to misinterpret results when not all of them appear in the histogram, and very easy for beginners (those who don’t read the dictionary very carefully) to just assume that auto scaling works.
I also wish the Dictionary entry for histogram fully explained how it works: apparently the height of a bar indicates the number of values between the bar’s left and right X values; and in the export-plot output the “x” value is the bar’s left side? But does the bar height indicate the number of values greater than the bar’s left X and less than or equal to the right X, or the number of values greater than or equal to the bar’s left X and less than the right X?