methionine | R Documentation |

## Weight gain for different methionine sources

### Description

Data consist of average body weight gain of chickens being treated
with one of the two methionine sources DLM and HMTBA.

### Usage

data(methionine)

### Format

A data frame with 9 observations on the following 3 variables:

`product`

a factor with levels `control`

, `DLM`

and `MHA`

denoting the treatments

`dose`

a numeric vector of methionine dose

`gain`

a numeric vector of average body weight gain

### Details

The dataset contains a common control measurement for the two treatments. More examples using this
dataset are found under `AR.2`

and `MM.2`

.

### Source

Kratzer. D. D. and Littell, R. C. (2006) Appropriate Statistical Methods to Compare
Dose Responses of Methionine Sources, *Poultry Science*, **85**, 947–954.

### Examples

## Fitting model with constraint on one parameter
met.ar.m1 <- drm(gain~dose, product, data = methionine,
fct = AR.3(), pmodels = list(~1, ~factor(product), ~factor(product)),
upperl = c(Inf, Inf, 1700, Inf, Inf))
plot(met.ar.m1, xlim=c(0,0.3), ylim=c(1450, 1800))
abline(h=1700, lty=1)
summary(met.ar.m1)