尝试运行混合效果模型时出现以下错误：
> LMER_MIXED <- as.data.frame(LMER_MIXED)
> m2 <- lmer(log_bid_price ~ . - state + (1|state), data = LMER_MIXED)
fixed-effect model matrix is rank deficient so dropping 1 column / coefficient
这是在使用 caret 包中的 findLinearCombos 来查看是否有任何可线性组合的列之后：
> LMER_MIXED <- cbind(cbind(LMER_DESIGN, state), log_bid_price)
> findLinearCombos(LMER_MIXED)
$linearCombos
list()
$remove
NULL
关于如何删除此警告并找到不可线性分离的列的任何想法？
> str(LMER_MIXED)
'data.frame': 11697 obs. of 63 variables:
$ (Intercept) : num 1 1 1 1 1 1 1 1 1 1 ...
$ month10 : num 0 0 0 0 0 0 0 0 0 0 ...
$ month11 : num 0 0 0 0 0 0 0 0 0 0 ...
$ month12 : num 0 0 0 0 0 0 0 0 0 0 ...
$ month2 : num 0 0 0 0 0 0 0 0 0 0 ...
$ month3 : num 0 0 0 0 0 0 0 0 0 0 ...
$ month4 : num 1 1 0 0 0 0 1 0 0 0 ...
$ month5 : num 0 0 1 1 1 1 0 1 0 0 ...
$ month6 : num 0 0 0 0 0 0 0 0 1 1 ...
$ month7 : num 0 0 0 0 0 0 0 0 0 0 ...
$ month8 : num 0 0 0 0 0 0 0 0 0 0 ...
$ month9 : num 0 0 0 0 0 0 0 0 0 0 ...
$ weekend1 : num 0 0 1 1 0 0 0 0 0 0 ...
$ weekendNone : num 0 0 0 0 0 0 0 0 0 0 ...
$ day_of_week1 : num 0 0 0 0 0 0 0 0 1 0 ...
...
我想问题是 Intercept 列是线性组合？