PROC CHART determines
the number of slices for the pie in the same way that it determines
the number of bars for vertical bar charts. Any slices of the pie
accounting for less than three print positions are grouped together
into an "OTHER" category.
The pie's
size is determined only by the SAS system options LINESIZE= and PAGESIZE=.
By default, the pie looks elliptical if your printer does not print
6 lines per inch and 10 columns per inch. To make a circular pie chart
on a printer that does not print 6 lines and 10 columns per inch,
use the LPI= option in the PROC CHART statement.
See the description
of LPI=value for
the formula that gives you the proper LPI= value for your printer.
If you try to create
a PIE chart for a variable with more than 50 levels, then PROC CHART
produces a horizontal bar chart instead.