PIEGRAPH

units

 The units for the radius and the centre coordinates are chosen by
 command qualifier:

 \PERCENT  --  means the coordinates are percentages of the window
 \GRAPH    --  means the coordinates are in graph units
 \WORLD    --  means the coordinates are in centimeters or inches,
               as chosen by the SET UNITS command (default centimeters)

wedge_definition

 A pie wedge is defined by the following values:

 w   wedge value (internally normalized, so units are irrelevant)
     the sum of all the wedge values will be 100% of the pie chart
 e   explode value (in percent of the radius) 
 f   fill pattern
            f  = 0   means no filling 
      1 <= |f| <= 10 means use hatch pattern f
     11 <= |f| <= 99 means use dot pattern 
            f  < 0   means the outline of the wedge is not drawn, 
                     but hatch pattern |f| is drawn 
 c   colour number for the fill pattern 
 o   colour number for the wedge outline