Rice fractional factorial experiment 1/2 2^6.
Rice fractional factorial experiment 1/2 2^6. Two reps with 2 blocks in each rep.
A data frame with 64 observations on the following 6 variables.
yieldgrain yield in tons/ha
repreplicate, 2 levels
blockblock within rep, 2 levels
trttreatment, levels (1) to abcdef
colcolumn position in the field
rowrow position in the field
Grain yield from a 2^6 fractional factorial experiment in blocks of 16 plots each, with two replications.
Gomez has some inconsistencies. One example:
Page 171: treatment (1) in rep 1, block 2 and rep 2, block 1.
Page 172: treatment (1) in Rep 1, block 1 and rep 2, block 1.
This data uses the layout shown on page 171.
Used with permission of Kwanchai Gomez.
Gomez, K.A. and Gomez, A.A.. 1984, Statistical Procedures for Agricultural Research. Wiley-Interscience. Page 171-172.
## Not run:
library(agridat)
data(gomez.fractionalfactorial)
dat <- gomez.fractionalfactorial
# trt abcdef has the highest yield
# Gomez, Figure 4.8
libs(desplot)
desplot(dat, yield~col*row,
# aspect unknown
text=trt, shorten="none", show.key=FALSE, cex=1,
main="gomez.fractionalfactorial - treatment & yield")
# Split treatment into individual factors
dat <- transform(dat,
a = -1 + 2 * grepl('a',trt),
b = -1 + 2 * grepl('b',trt),
c = -1 + 2 * grepl('c',trt),
d = -1 + 2 * grepl('d',trt),
e = -1 + 2 * grepl('e',trt),
f = -1 + 2 * grepl('f',trt))
# Gomez table 4.24, trt SS totalled together.
# Why didn't Gomez nest block within rep?
m0 <- lm(yield ~ rep * block + trt, dat)
anova(m0)
# Gomez table 4.24, trt SS split apart
m1 <- lm(yield ~ rep * block + (a+b+c+d+e+f)^3, dat)
anova(m1)
libs(FrF2)
aliases(m1)
MEPlot(m1, select=3:8,
main="gomez.fractionalfactorial - main effects plot")
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