library(lme4)
data(sleepstudy)
sleepstudy[1:10,]
str(sleepstudy)
xyplot(Reaction ~ Days | Subject, sleepstudy, type = c("g","p","r"),
       index = function(x,y) coef(lm(y ~ x))[1],
       xlab = "Days of sleep deprivation",
       ylab = "Average reaction time (ms)", aspect = "xy")

lm1<-lm(Reaction~Days+Subject,sleepstudy)
summary(lm1)

#Random Slopes
(fm1 <- lmer(Reaction ~ Days + (Days|Subject), sleepstudy))
summary(fm1)

#Random Intercepts and Slopes
(fm2 <- lmer(Reaction ~ Days + (1|Subject) + (0+Days|Subject), sleepstudy))
summary(fm2)

anova(fm1, fm2)

dotplot(ranef(fm1, postVar = TRUE))
qqmath(ranef(fm1, postVar=TRUE))