if( !require('drc') ){
    install.packages('drc', dependencies=TRUE, repos='http://cran.rstudio.com/')
}
library(drc) # get the dataset methionine

if( !require('nlme') ){
    install.packages('nlme', dependencies=TRUE, repos='http://cran.rstudio.com/')
}
library(nlme)

library(lattice)

methionine$product2 = methionine$product
mask = methionine$product2 =='control'
methionine$product2[mask] ='DLM'
levels(methionine$product2)= c('DLM','DLM','MHA')
print(head(methionine))

source('SSoneMinusExp.R')

#Fit a model on ail of the data:
#
methionine.m0 = nls(gain ~ SSoneMinusExp(dose, a, b, c), data=methionine)
print(summary(methionine.m0))

# Fit each model separately:
#
methionine.m1 = nlsList(gain ~ SSoneMinusExp(dose, a, b, c) | product2, data=methionine)
print(summary(methionine.m1))