Histograms
  There are 3 options for plotting simple histograms:
  (1) Data unaltered: will plot the raw data as it appears in the spreadsheet column. This option will automatically label the y axis, but no labels are put on the x axis, so that individual customized labels can be added subsequently.
  (2) Frequency histogram: will accumulate the number of data points occurring between the intervals specified either (a) automatically from a starting value below the lowest data point, or (b) from starting and incremental values you type into the fields provided by clicking the "by specified values" button which is only available for this option; or
  (3) Cumulative histogram: will accumulate the cumulative sums of consecutive data points and plot these as a proportion of the total (indicated on the y axis). Labels can be added to the x axis after the graph is plotted.
  Only one column can be plotted at a time. The fill pattern will also be the same in each column. If you wish to have different fill patterns, you will need to export the plot to a drawing program and alter them individually.
  See Plotting Routines for more general information as well.