# 
flick <- read.delim("http://myweb.uiowa.edu/pbreheny/data/flicker.txt")


# 
model1 <- lm(flick$Flicker ~ flick$Color)
anova(model1)


# 
model1 <- lm(flick$Flicker ~ flick$Color) # Full model
model0 <- lm(flick$Flicker ~ 1) # Model with just the intercept (reduced model)

RSS1 <- sum(model1$residuals^2)
RSS0 <- sum(model0$residuals^2)

# formula used in class to find explained variability: 
(RSS0-RSS1)/RSS0


# 
summary(model1)


# out.width='.6\\linewidth'
boxplot(flick$Flicker~flick$Color, col=c("blue", "brown", "green"))


# 
fit <- aov(flick$Flicker~flick$Color)

TukeyHSD(fit)


# 
pairwise.t.test(flick$Flicker, flick$Color, p.adj = "bonf")


# 
pairwise.t.test(flick$Flicker, flick$Color, p.adj = "none")