The following data set contains the input data that are used in this example:

data xy_data;
   input x y;
   datalines;
 0.0 1.0
 0.5 0.9
 1.0 0.7
 1.5 1.5
 1.9 2.0
 2.5 2.4
 3.0 3.2
 3.5 2.0
 4.0 2.7
 4.5 3.5
 5.0 1.0
 5.5 4.0
 6.0 3.6
 6.6 2.7
 7.0 5.7
 7.6 4.6
 8.5 6.0
 9.0 6.8
10.0 7.3
;