epa<-read.table("http://www.sandgquinn.org/stonehill/MA225/notes/09tstcar.csv",sep=",",fill=TRUE,header=TRUE)
trnsdata<-epa[ which(epa$C.H=='C' & epa$car.truck=='C' & epa$trns %in% c('L5','L6','M5','M6')),]
trnsdata$auto.manual<-substr(trnsdata$trns,1,1)
trnsdata$trns.gears<-substr(trnsdata$trns,2,2)
trnsdata2<-subset(trnsdata,,select=c(mpg,auto.manual,trns.gears,rhp))
attach(trnsdata2)