chain <- read.delim("chaindata.txt")
chain
PL1 <- subset(chain, talker="PL1")

PL1[18:32] 

plot(PL1$y8,PL1$y9)
cor(PL1$y8, PL1$y9)

pairs(PL1[,c("y2", "y5", "y15")])

summary(lm(y15 ~ y2 + y6 + y5, data = PL1))

chain.lm.y = lm(y15 ~ y2 + y6 + y5 + x6 + x5, data=PL1) 
chain.lm.y
summary(chain.lm.y)

chain.lm.y.simple = lm(y15 ~ y2, data=PL1) 
plot(PL1$y2, PL1$y15)
abline(chain.lm.y.simple)

plot(fitted(chain.lm.y.simple), residuals(chain.lm.y.simple), xlab="fitted", ylab="Residuals")
abline(h=0)