Pie Charts
   After selecting the one sample you require, you have 3 options for plotting a simple pie chart. You can plot by the values in the spreadsheet (without values no values, or by the actual values) or by each as a percentage of the total (percentages (%)).
  The values plotted beside each sector will use the number of decimal places, font, colour, size, and style options set in the Preferences dialog. Each sector's area will be shaded by a different shade.
  See Plotting Routines for more general information as well.