GrainR Documentation

Grain data from Preece (1982, Table 5)

Description

This dataset presents 9 paired data corresponding to the grain yields of Great Northern and Big Four oats grown in "adjacent" plots.

Usage

data(Grain)

Format

A dataframe with 9 rows and 3 columns:

[,1] Year factor
[,2] GreatNorthern numeric grain yield (bushels per acre)
[,3] BigFour numeric grain yield

Source

LeClerg, E.L., Leonard, W.H. & Clark, A.G. (1962) Field Plot Technique. Burgess: Minneapolis.

References

Preece, D.A. (1982) t is for trouble (and textbooks): a critique of some examples of the paired-samples t-test. The Statistician, 31 (2), 169-195.

Examples

data(Grain)

# Usual visualization for paired data (2 clusters?)
with(Grain, plot(paired(GreatNorthern,BigFour)))

# Are they actually "adjacent" plots? 
# Why this variable Year?
# Is there any time trend?
with(Grain, plot(Year,GreatNorthern,type="o"))
with(Grain, plot(Year,BigFour,type="o"))