specifies the height
of By line text; by default By line-height is 1. If you specify HBY=0, the BY headings are suppressed. For
a description of units, see Specifying Units of Measurement.
Note: If a value for units is not specified, the current units associated
with the GUNIT graphics option are used.
Details
When you use a BY statement
with a SAS/GRAPH procedure to process a data set in subgroups, each
graph produced by that procedure is headed by a By line that displays
the BY variables and their values that define the current subgroup.