agridat (version 1.23)

heath.radish.uniformity: Uniformity trial of radish

Description

Uniformity trial of radish in four containers.

Usage

data("heath.radish.uniformity")

Format

A data frame with 400 observations on the following 4 variables.

row

row

col

column

block

block

yield

weight per plant, grams

Details

Weight of 399 radish plants grown at 1 inch x 1 inch spacing in four plastic basins. Seed wetted 1968-02-15, planted 1968-02-17, harvested 1968-03-26.

Heath said, Most of the large plants were round the edges...one important source of variation might have been competition for light.

References

None

Examples

if (FALSE) {
  require(agridat)
  data(heath.radish.uniformity)
  dat <- heath.radish.uniformity
  libs(desplot, dplyr)
  desplot(dat, yield ~ col*row|block,
          aspect=1,
          main="heath.radish.uniformity")

  # Indicator for border/interior plants
  dat <- mutate(dat,
                inner = row > 1 & row < 10 & col >  1 & col < 10)
  # Heath has 5.80 and 9.63 (we assume this is a typo of 9.36)
  dat <- group_by(dat, inner)
  summarize(dat, mean=mean(yield, na.rm=TRUE))
  # Interior plots are significantly lower yielding
  anova(aov(yield ~ block + inner, dat))
  # lattice::bwplot(yield ~ inner, dat, horiz=0)
  # similar to Heath fig 2-2
  # lattice::histogram( ~ yield|inner, dat, layout=c(1,2), n=20)
}