具有1级和2级变量的纵向数据的R命令结构

我有不同年份的儿童考试成绩和人口统计数据（纵向数据），需要在上面运行几个比较模型。我对如何在

R

中设置级别1和级别2变量感到困惑

我的数据帧（df）：

我想运行至少两个模型并进行比较，但我不确定如何将时变协变量与时变协变量分开。我试过这些：

summary(fix <-lme(MathScore ~ Gender+Race+DepressionScore+MemoryScore, random= Year|Student, data=df, na.action="na.omit")

summary(fix2 <- lme(MathScore ~ 1+Gender+Race+DepressionScore+MemoryScore, random=~1|Year, data=df, na.action=na.omit)) 

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summary（fix您在学生中嵌套了年份，因此随机截距模型的命令：

summary（fix您在学生中嵌套了年份，因此随机截距模型的命令：

摘要（修复可能重复的
summary(fix <-lme(MathScore ~ Gender+Race+DepressionScore+MemoryScore, random= Year|Student, data=df, na.action="na.omit")

summary(fix2 <- lme(MathScore ~ 1+Gender+Race+DepressionScore+MemoryScore, random=~1|Year, data=df, na.action=na.omit)) 

summary(fix <-lme(MathScore ~ Gender+Race+DepressionScore+MemoryScore, random= ~1|Student/Years, data=df, na.action="na.omit")

ddply(dat, "Student", transform, mean.std.DepressionScore  = mean(DepressionScore))
ddply(dat, "Student", transform, mean.std.MemoryScore= mean(MemoryScore))

df$time.DepressionScore <- df$DepressionScore-df$mean.std.DepressionScore
df$time.MemoryScore<- df$MemoryScore-df$mean.std.MemoryScore

summary(fix <-lme(MathScore ~ Gender+Race+mean.std.DepressionScore+time.DepressionScore+mean.std.MemoryScore+time.MemoryScore + Year, random= ~1|Year/Student, data=df, na.action="na.omit")