old_faithful <- read.csv("~/Downloads/old_faithful.csv")
old.f.tot=old_faithful
# WHERE SHOULD WE BREAK IT? HOW DO WE KNOW?
hist(old.f.tot)
old.f.small<-old.f.tot[old.f.tot$Duration<198,]
old.f.big<-old.f.tot[old.f.tot$Duration>198,]
#WHAT DO WE MAKE OUR GRAPH SO WE CAN SEE IT?
max(old.f.tot$Duration)
min(old.f.tot$Duration)
min(old.f.tot$Interval)
max(old.f.tot$Interval)
# LET'S MAKE AN OLD.F GRAPH
plot(old.f.small,xlim=c(90,320),ylim=c(35,110),col='blue',pch=19)
points(old.f.big,pch=19,col='red')
abline(lm(old.f.small$Interval~old.f.small$Duration),col='blue')
abline(lm(old.f.big$Interval~old.f.big$Duration),col='red')
abline(lm(old.f.tot$Interval~old.f.tot$Duration))
# HOW GOOD IS IT?
cor(old.f.tot)
cor(old.f.small)
cor(old.f.big)