plot(ChamberConc ~ time,data=ccl4data,xlab="Time (hours)",
         xlim=range(c(0,ccl4data$time)),
         ylab="Chamber Concentration (ppm)",log="y")
ccl4data.avg<-aggregate(ccl4data$ChamberConc,
                        by=ccl4data[c("time","initconc")],mean)
points(x ~ time,data=ccl4data.avg,pch=16)Run the code above in your browser using DataLab