怎么用把几个loess曲线放在一个图里，用不同颜色表明，附sas code
proc loess data=almodel daysofTm90=year daysofTm95=year daysofTm98=year daysofTm100=year daysofTm102=year daysofTm105=year/overlay;
run;
上面的code不对