agricolae (version 1.1-5)

plots: Data for an analysis in split-plot

Description

Experimental data in blocks, factor A in plots and factor B in sub-plots.

Usage

data(plots)

source

International Potato Center. CIP

Examples

library(agricolae)
data(plots)
str(plots)
plots[,1] <-as.factor(plots[,1])
# split-plot analysis
model <- aov(yield ~ block + A + Error(plot)+ B + A:B, data=plots)
summary(model)
attach(plots)
b<-nlevels(B)
a<-nlevels(A)
r<-nlevels(block)
dfa <- df.residual(model$plot)
Ea <-deviance(model$plot)/dfa
dfb <- df.residual(model$Within)
Eb <-deviance(model$Within)/dfb
Eab <- (Ea +(b-1)*Eb)/(b*r)
# Satterthwaite
dfab<-(Ea +(b-1)*Eb)^2/(Ea^2/dfa +((b-1)*Eb)^2/dfb)
# Comparison A, A(b1), A(b2), A(b3)
comparison1 <-LSD.test(yield,A,dfa,Ea)
comparison2 <-LSD.test(yield[B=="b1"],A[B=="b1"],dfab,Eab)
comparison3 <-LSD.test(yield[B=="b2"],A[B=="b2"],dfab,Eab)
comparison4 <-LSD.test(yield[B=="b3"],A[B=="b3"],dfab,Eab)
# Comparison B, B(a1), B(a2)
comparison5 <-LSD.test(yield,B,dfb,Eb)
comparison6 <-LSD.test(yield[A=="a1"],B[A=="a1"],dfb,Eb)
comparison7 <-LSD.test(yield[A=="a2"],B[A=="a2"],dfb,Eb)
detach(plots)