Heights of Barley Plants
Average heights for 15 genotypes of barley recorded over 9 years.
barleyHeights
A data frame with 135 observations on the following 3 variables.
heightaverage height over 4 replicates (cm)
yeara factor with 9 levels 1974 to 1982
genotypea factor with 15 levels 1:15
Aastveit, A. H. \& Martens, H. (1986). ANOVA interactions interpreted by partial least squares regression. Biometrics, 42, 829–844.
Chadoeuf, J \& Denis, J B (1991). Asymptotic variances for the multiplicative interaction model. J. App. Stat. 18(3), 331–353.
set.seed(1)
## Fit AMMI-1 model
barleyModel <- gnm(height ~ year + genotype + Mult(year, genotype),
data = barleyHeights)
## Get row and column scores with se's
gamma <- getContrasts(barleyModel, pickCoef(barleyModel, "[.]y"),
ref = "mean", scaleWeights = "unit")
delta <- getContrasts(barleyModel, pickCoef(barleyModel, "[.]g"),
ref = "mean", scaleWeights = "unit")
## Corresponding CI's similar to Chadoeuf & Denis (1991) Table 8
## (allowing for change in sign)
gamma[[2]][,1] + (gamma[[2]][,2]) %o% c(-1.96, 1.96)
delta[[2]][,1] + (delta[[2]][,2]) %o% c(-1.96, 1.96)
## Multiplier of row and column scores
height <- matrix(scale(barleyHeights$height, scale = FALSE), 15, 9)
R <- height - outer(rowMeans(height), colMeans(height), "+")
svd(R)$d[1]Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.