agridat (version 1.12)

gilmour.slatehall: Slate Hall Farm 1978

Description

Yields for a trial at Slate Hall Farm in 1978.

Format

A data frame with 150 observations on the following 5 variables.

row

Row

col

Column

yield

Yield (grams/plot)

gen

Genotype factor, 25 levels

rep

Rep factor, 6 levels

Details

The trial was a balanced lattice with 25 varieties in 6 replicates. The plot size was 1.5 meters by 4 meters, so the total area was 15 x 1.5 meters by 10 x 4 meters. The 'rep' labels are arbitrary (no rep labels appeared in the source data). Each row within a rep is an (incomplete) block.

Examples

# NOT RUN {
data(gilmour.slatehall)
dat <- gilmour.slatehall

desplot(yield ~ col * row, dat, num=gen,
        out1=rep, main="gilmour.slatehall")

# }
# NOT RUN {
# Model 4 of Gilmour et al 1997
require(asreml)
dat <- transform(dat, xf=factor(col), yf=factor(row))
dat <- dat[order(dat$xf, dat$yf), ]
m4 <- asreml(yield ~ gen + lin(row), data=dat,
             random = ~ dev(row) + dev(col),
             rcov = ~ ar1(xf):ar1(yf))
coef(m4)$fixed[1] # linear row
# [1] 31.72252 # (sign switch due to row ordering)

require(lucid)
vc(m4)
##      effect component std.error z.ratio constr
##    dev(row) 20290     10260         2      pos
##    dev(col)  2519      1959         1.3    pos
##  R!variance 23950      4616         5.2    pos
##    R!xf.cor     0.439     0.113     3.9  uncon
##    R!yf.cor     0.125     0.117     1.1  uncon

plot(variogram(m4))
# }