agridat (version 1.23)

vaneeuwijk.drymatter: Multi-environment trial of maize, dry matter content

Description

Multi-environment trial of maize, dry matter content

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).

Used with permission of Fred van Eeuwijk.

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. https://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. https://doi.org/10.1007/BF01677552

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

Examples

if (FALSE) {
  
  library(agridat)
  data(vaneeuwijk.drymatter)
  dat <- vaneeuwijk.drymatter
  dat <- transform(dat, year=factor(year))
  dat <- transform(dat, env=factor(paste(year,site)))

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

  
  # 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
  libs(lme4)
  libs(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)  0.3187  0.5645
  ##    year:site (Intercept)  7.735   2.781 
  ## site:variety (Intercept)  0.03502 0.1871
  ##         year (Intercept)  6.272   2.504 
  ##      variety (Intercept)  0.4867  0.6976
  ##         site (Intercept)  6.504   2.55  
  ##     Residual          0.8885  0.9426
  
}