brandle.rape {agridat} | R Documentation |
Rape seed yields for 5 genotypes, 3 years, 9 locations.
A data frame with 135 observations on the following 4 variables.
gen
genotype
year
year, numeric
loc
location, 9 levels
yield
yield, kg/ha
The yields are the mean of 4 reps.
Note, in table 2 of Brandle, the value of Triton in 1985 at Bagot is shown as 2355, but should be 2555 to match the means reported in the paper.
Brandle, JE and McVetty, PBE. (1988). Genotype x environment interaction and stability analysis of seed yield of oilseed rape grown in Manitoba. Canadian Journal of Plant Science, 68, 381–388.
Used with permission of P. McVetty.
data(brandle.rape) dat <- brandle.rape require(lattice) dotplot(gen~yield|loc, dat, group=year, auto.key=list(columns=3), main="brandle.rape, yields per location", ylab="Genotype") # Matches table 4 of Brandle round(tapply(dat$yield, dat$gen, mean),0) ## Not run: # Brandle reports variance components: # sigma^2_gl: 9369 gy: 14027 g: 72632 resid: 150000 # Brandle analyzed rep-level data, so the residual variance is different. # The other components are matched by the following analysis. require(lme4) require(lucid) dat$year <- factor(dat$year) m1 <- lmer(yield ~ year + loc + year:loc + (1|gen) + (1|gen:loc) + (1|gen:year), data=dat) vc(m1) ## grp var1 var2 vcov sdcor ## gen:loc (Intercept) <NA> 9363 96.76 ## gen:year (Intercept) <NA> 14030 118.4 ## gen (Intercept) <NA> 72630 269.5 ## Residual <NA> <NA> 75010 273.9 ## End(Not run)