Create data set. REFLIB.IRIS contains petal and sepal measurements for the flowers of three iris species, which are identified by species numbers. 
data reflib.iris;
   input sepallen sepalwid petallen petalwid spec_no;
   datalines;
50 33 14 02 1
64 28 56 22 3
...more data lines...
63 33 60 25 3
53 37 15 02 1
;