growth <- read.table("growth.dat",header=T)
growth <- growth[,c("trt","advplt")]
growth$logadvplt <- log10(1+growth$advplt)
 
growth$BA <- c(rep(0,4),rep(0.44,4),rep(4.4,3),rep(NA,9),0)[1+growth$trt]
growth$TDZ <- c(rep(c(0,0.2,2,20),3)[1:11],rep(NA,9),0)[1+growth$trt]
growth$code <- c(0:9,"a",rep(NA,9),"C")[1+growth$trt]

growth$trt <- factor(growth$trt)
growth$BA <- factor(growth$BA)
growth$TDZ <- factor(growth$TDZ)
growth <- growth[!is.na(growth$advplt),]

growth.zero <- growth[growth$advplt>0,]

growth.fit <- lm(logadvplt~trt,growth)
growth.zero.fit <- lm(logadvplt~trt,growth.zero)

growth$ba <- ordered( codes( growth$BA ) )
growth$tdz <- ordered( codes( growth$TDZ ) )
growth.full <- aov( logadvplt ~ ba * tdz, growth )
growth.add <- aov( logadvplt ~ ba + tdz, growth )