### Name: CO2 ### Title: Carbon Dioxide uptake in grass plants ### Aliases: CO2 ### Keywords: datasets ### ** Examples require(stats); require(graphics) coplot(uptake ~ conc | Plant, data = CO2, show.given = FALSE, type = "b") ## fit the data for the first plant fm1 <- nls(uptake ~ SSasymp(conc, Asym, lrc, c0), data = CO2, subset = Plant == 'Qn1') summary(fm1) ## fit each plant separately fmlist <- list() for (pp in levels(CO2$Plant)) { fmlist[[pp]] <- nls(uptake ~ SSasymp(conc, Asym, lrc, c0), data = CO2, subset = Plant == pp) } ## check the coefficients by plant sapply(fmlist, coef)