Birth weight of lambs from different lines/sires
Birth weight of lambs from different lines/sires
data("harville.lamb")A data frame with 62 observations on the following 4 variables.
linegenotype line number
siresire number
damagedam age, class 1,2,3
weightlamb birth weight
Weight at birth of 62 lambs. There were 5 distinct lines.
Some sires had multiple lambs. Each dam had one lamb.
The age of the dam is a category: 1 (1-2 years), 2 (2-3 years) or 3 (over 3 years).
Note: Jiang, gives the data in table 1.2, but there is a small error. Jiang has a weight 9.0 for sire 31, line 3, age 3. The correct value is 9.5.
David A. Harville and Alan P. Fenech (1985). Confidence Intervals for a Variance Ratio, or for Heritability, in an Unbalanced Mixed Linear Model. Biometrics, 41, 137-152. https://doi.org/10.2307/2530650
Jiming Jiang, Linear and Generalized Linear Mixed Models and Their Applications. Table 1.2.
Andre I. Khuri, Linear Model Methodology. Table 11.5. Page 368. https://books.google.com/books?id=UfDvCAAAQBAJ&pg=PA164
Daniel Gianola, Keith Hammond. Advances in Statistical Methods for Genetic Improvement of Livestock. Table 8.1, page 165.
## Not run:
library(agridat)
data(harville.lamb)
dat <- harville.lamb
dat <- transform(dat, line=factor(line), sire=factor(sire), damage=factor(damage))
library(lattice)
bwplot(weight ~ line, dat,
main="harville.lamb",
xlab="line", ylab="birth weights")
if(0){
libs(lme4, lucid)
m1 <- lmer(weight ~ -1 + line + damage + (1|sire), data=dat)
summary(m1)
vc(m1) # Khuri reports variances 0.5171, 2.9616
## grp var1 var2 vcov sdcor
## sire (Intercept) <NA> 0.5171 0.7191
## Residual <NA> <NA> 2.962 1.721
}
## End(Not run)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.