agridat (version 1.23)

corsten.interaction: Multi-environment trial of corn

Description

The data is the yield (kg/acre) of 20 genotypes of corn at 7 locations.

Format

A data frame with 140 observations on the following 3 variables.

gen

genotype, 20 levels

loc

location, 7 levels

yield

yield, kg/acre

Details

The data is used by Corsten & Denis (1990) to illustrate two-way clustering by minimizing the interaction sum of squares.

In their paper, the labels on the location dendrogram have a slight typo. The order of the loc labels shown is 1 2 3 4 5 6 7. The correct order of the loc labels is 1 2 4 5 6 7 3.

Used with permission of Jean-Baptiste Denis.

Examples

if (FALSE) {

library(agridat)
data(corsten.interaction)
dat <- corsten.interaction

libs(reshape2)
m1 <- melt(dat, measure.var='yield')
dmat <- acast(m1, loc~gen)

# Corsten (1990) uses this data to illustrate simultaneous row and
# column clustering based on interaction sums-of-squares.
# There is no (known) function in R to reproduce this analysis
# (please contact the package maintainer if this is not true).
# For comparison, the 'heatmap' function clusters the rows and
# columns _independently_ of each other.
heatmap(dmat, main="corsten.interaction")

}