可以试试在数据集中生成一个新变量例如x1x2 = x1*x2,
x1x2纳入模型表示x1与x2交互作用的变量名.
http://support.sas.com/documenta ... tug_reg_sect056.htm
data acetyl;
input x1-x4 @@;
x1x2 = x1 * x2;
x1x1 = x1 * x1;
label x1 = 'reactor temperature(celsius)'
x2 = 'h2 to n-heptone ratio'
x3 = 'contact time(sec)'
x4 = 'conversion percentage'
x1x2= 'temperature-ratio interaction'
x1x1= 'squared temperature';
datalines;
1300 7.5 .012 49 1300 9 .012 50.2 1300 11 .0115 50.5
1300 13.5 .013 48.5 1300 17 .0135 47.5 1300 23 .012 44.5
1200 5.3 .04 28 1200 7.5 .038 31.5 1200 11 .032 34.5
1200 13.5 .026 35 1200 17 .034 38 1200 23 .041 38.5
1100 5.3 .084 15 1100 7.5 .098 17 1100 11 .092 20.5
1100 17 .086 29.5
;
run;
proc reg data=acetyl outvif;
model x4=x1 x2 x3 x1x2 x1x1;
run;