You can use the HEIGHT= (or H=) option to specify the height of the plotting symbol. You can specify a value for height and a unit of measurement. Valid units are

• percentage of the display area (PCT)
• inches (IN)
• centimeters (CM)
• points (PT)
• character cells (CELL), which is the default unit.

The SYMBOL1 statement below specifies a triangle plotting symbol that is 1 centimeter high.

     symbol1 value=triangle height=1 cm color=black;
     proc gplot data=clinic.totals2000;         
        plot newadmit*month; 
     run;