methionine {drc} | R Documentation |
Data consist of average body weight gain of chickens being treated with one of the two methionine sources DLM and HMTBA.
data(methionine)
A data frame with 9 observations on the following 3 variables:
product
control
, DLM
and MHA
denoting the treatmentsdose
gain
The dataset contains a common control measurement for the two treatments.
Kratzer. D. D. and Littell, R. C. (2006) Appropriate Statistical Methods to Compare Dose Responses of Methionine Sources, Poultry Science, 85, 947–954.
Schutte, J. B. and de Jong, J. (1996) Biological efficacy of DL-methinonine hydroxy analog free acid compared to DL-methionine in broiler chicks as determined by performance and breast meat yield, Agribiol. Res., 49, 74–82.
## Fitting model with constraint on one parameter met.m1<-drm(gain~dose, product, data=methionine, fct=AR.3(), pmodels = list(~1, ~factor(product), ~factor(product)), upperl=c(Inf, Inf,1700,Inf,Inf)) summary(met.m1)