agridat (version 1.12)

garber.multi.uniformity: Uniformity trials of oat hay and wheat

Description

Uniformity trials of oat straw and wheat

Format

A data frame with 270 observations on the following 4 variables.

row

row ordinate

col

column ordinate

oats

yield of oat hay

wheat

yield of wheat grain

Details

In 1923 the field was planted to oats and harvested as hay. In 1924 the field was planted to wheat and harvested for grain.

Garber: "Plots 211 to 214, and 261 to 264, [note, these are rows 11-14, columns 5-6] inclusive, were eliminated from this study because of the fact that a few years ago a straw stack had stood on or in the vicinity...which undoubtedly accounts for the relatively high yields on plots 261 to 264, inclusive."

Note: The source document contained mean-subtracted yields. The oat yield in row 22, column 5 was given as +59.7. This is obviously incorrect, since the negative yields all end in '.7' and positive yields all ended in '.3'. We used -59.7 as the centered yield value and added the mean of 1883.7 to all centered yields to obtain absolute yields.

Examples

# NOT RUN {
data(garber.multi.uniformity)
dat <- garber.multi.uniformity

desplot(oats ~ col*row, data=dat, flip=TRUE, tick=TRUE,
        main="garber.multi.uniformity oats")
desplot(wheat ~ col*row, data=dat, flip=TRUE, tick=TRUE,
        main="garber.multi.uniformity wheat")
with(dat, cor(oats, wheat)) # = .37 matches Garber

# }