options nocenter;
data a1; 
   infile 'U:\.www\datasets512\Ch07ta09.dat';
   input cycles chrate temp;
proc print data=a1; 
run;

*Defining the squares and crossproduct terms;
data a1; set a1;
  chrate2=chrate*chrate;
  temp2=temp*temp;
  ct=chrate*temp;

proc reg data=a1;
   model cycles=chrate temp chrate2 temp2 ct;
run;

*Checking the pairwise correlations among variables;
proc corr data=a1;
   var chrate temp chrate2 temp2 ct;
run;

*Define new data set with same info, different 
   explanatory variable names.  The keep tells SAS 
   which variables to store.  The others are thrown out;
data a2; set a1; 
   schrate=chrate; stemp=temp;
   keep cycles schrate stemp;

*standardize/center the variables and put them in
    data set a3;
proc standard data=a2 out=a3 mean=0 std=1;
   var schrate stemp;

proc print data=a3;
run;

*Defining the squares and crossproduct terms;
data a3; set a3;
  schrate2=schrate*schrate;
  stemp2=stemp*stemp;
  sct=schrate*stemp;

proc reg data=a3;
  model cycles=schrate stemp schrate2 stemp2 sct;
run;