用sas做回归分析;
proc reg data=engine graphics;
model power=speed;
plot power*speed/conf95 pred95;
symbol v=star;
run;
以上是可以画出散点图和置信区间图的,下面怎么就不可以了?
data engine2;
set engine;
speedsq=speed**2;
run;
proc reg data=engine2 graphics;
model power=speed speedsq;
plot power*speed/conf95 pred95;
symbol v=star;
这里的graphics怎么用?