agridat (version 1.16)

vaneeuwijk.drymatter: Dry matter content for Dutch maize varieties in multiple years/sites

Description

Dry matter content for Dutch maize varieties in multiple years/sites

Usage

data("vaneeuwijk.drymatter")

Format

A data frame with 168 observations on the following 5 variables.

year

year

site

site, 4 levels

variety

variety, 6 levels

y

dry matter percent

Details

Percent dry matter is given.

Site codes are soil type classifications: SS=Southern Sand, CS=Central Sand, NS=Northern Sand, RC=River Clay.

These data are a balanced subset of the data analyzed in van Eeuwijk, Keizer, and Bakker (1995b) and Kroonenberg, Basford, and Ebskamp (1995).

References

Kroonenberg, P.M., Basford, K.E. & Ebskamp, A.G.M. (1995). Three-way cluster and component analysis of maize variety trials. Euphytica, 84(1):31-42. http://doi.org/10.1007/BF01677554

van Eeuwijk, F.A., Keizer, L.C.P. & Bakker, J.J. Van Eeuwijk. (1995b). Linear and bilinear models for the analysis of multi-environment trials: II. An application to data from the Dutch Maize Variety Trials Euphytica, 84(1):9-22. http://doi.org/10.1007/BF01677552

Hardeo Sahai, Mario M. Ojeda. Analysis of Variance for Random Models, Volume 1. Page 261.

Examples

# NOT RUN {
data(vaneeuwijk.drymatter)
dat <- vaneeuwijk.drymatter
dat <- transform(dat, year=factor(year))
dat <- transform(dat, env=factor(paste(year,site)))

if(require(HH)){
  HH::interaction2wt(y ~ year+site+variety,dat,rot=c(90,0),
                     x.between=0, y.between=0,
                     main="vaneeuwijk.drymatter")
}

# }
# NOT RUN {
  # anova model
  m1 <- aov(y ~ variety+env+variety:env, data=dat)
  anova(m1) # Similar to VanEeuwijk table 2
  m2 <- aov(y ~ year*site*variety, data=dat)
  anova(m2) # matches Sahai table 5.5

  # variance components model
  require(lme4)
  require(lucid)
  m3 <- lmer(y ~ (1|year) + (1|site) + (1|variety) +
               (1|year:site) + (1|year:variety) + (1|site:variety),
             data=dat)
  vc(m3) # matches Sahai page 266
  ##          grp        var1 var2    vcov  sdcor
  ## year:variety (Intercept) <NA> 0.3187  0.5645
  ##    year:site (Intercept) <NA> 7.735   2.781 
  ## site:variety (Intercept) <NA> 0.03502 0.1871
  ##         year (Intercept) <NA> 6.272   2.504 
  ##      variety (Intercept) <NA> 0.4867  0.6976
  ##         site (Intercept) <NA> 6.504   2.55  
  ##     Residual        <NA> <NA> 0.8885  0.9426
# }
# NOT RUN {
# }

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