如代码所示，我的PM1_p是在model3中的 但是跑出来就报错说not in model，烦请会的朋友指点一下~超级感谢
> model3 <- geeglm(WL_z~rcs(PM1_p,5)+motherage+edu+mjob+income+BMI_C+PA1+child_sex+season+
+ ns(p_T,df=4)+parity1+smoking+feed+delivery,
+ id=ID,corstr = "exch",std.err = "san.se",data = r_e)
>
> an<-anova(model3)
>
>
> Predict(model3,PM1_p)
Error in Predict(model3, PM1_p) : predictors(s) not in model: PM1_p