我想做一个 MAM,但我很难删除一些术语:
full.model<-glm(SSB_sq~Veg_height+Bare+Common+Birds_Foot+Average_March+Average_April+
Average_May+Average_June15+Average_June20+Average_June25+Average_July15
+Average_July20+Average_July25,family="poisson")
summary(full.model)
我相信我必须删除这些条款才能像这样启动 MAM:
model1<-update(full.model,~.-Veg_height:Bare:Common:Birds_Foot:Average_March
:Average_April:Average_May:Average_June15:Average_June20:Average_June25:
Average_July15:Average_July20:Average_July25,family="poisson")
summary(model1)
anova(model1,full.model,test="Chi")
但我得到这个输出:
anova(model1,full.model,test="Chi")
Analysis of Deviance Table
Model 1: SSB_sq ~ Veg_height + Bare + Common + Birds_Foot + Average_March +
Average_April + Average_May + Average_June15 + Average_June20 +
Average_June25 + Average_July15 + Average_July20 + Average_July25
Model 2: SSB_sq ~ Veg_height + Bare + Common + Birds_Foot + Average_March +
Average_April + Average_May + Average_June15 + Average_June20 +
Average_June25 + Average_July15 + Average_July20 + Average_July25
Resid. Df Resid. Dev Df Deviance P(>|Chi|)
1 213 237.87
2 213 237.87 0 0
我尝试在 model1 中使用加号而不是冒号,因为我在阅读笔记时正抓着稻草,但同样的事情发生了。
为什么我的两个型号都一样?我试过在谷歌上搜索,但我不太擅长术语,所以我的搜索并没有带来太多。