
This dataset presents 15 paired data corresponding to the final height of corn data (Zea Mays), one produced by cross-fertilization and the other by self-fertilization. These data were used by Fisher (1936) and were published in Andrews and Herzberg (1985).
data(Corn)
A dataframe with 15 rows and 4 columns:
[,1] | pair | numeric | |
[,2] | pot | numeric | |
[,3] | Crossed | numeric | plant height (inches) |
[,4] | Self | numeric | plant height |
Andrews, D. and Herzberg, A. (1985) Data: a collection of problems from many fields for the student and research worker. New York: Springer.
Fisher, R.A. (1936) The design of Experiments. Oliver & Boyd: London
# NOT RUN {
data(Corn)
# Visualizing two outliers
with(Corn,slidingchart(paired(Crossed,Self)))
# Very bad matching in these data
with(Corn,cor.test(Crossed,Self))
with(Corn,winsor.cor.test(Crossed,Self))
# So the two-sample test is slightly
# more interesting than the paired test
with(Corn,t.test(Crossed,Self,var.equal=TRUE))
with(Corn,t.test(Crossed,Self,paired=TRUE))
# The Pitman-Morgan test is influenced by the two outliers
with(Corn,Var.test(paired(Crossed,Self)))
with(Corn,grambsch.Var.test(paired(Crossed,Self)))
with(Corn,bonettseier.Var.test(paired(Crossed,Self)))
# Lastly, is there a pot effect?
with(Corn,plot(paired(Crossed,Self)))
with(Corn,plot(paired(Crossed,Self),group=pot))
# }
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