agridat (version 1.23)

gomez.fractionalfactorial: Fractional factorial of rice, 1/2 2^6 = 2x2x2x2x2x2

Description

Fractional factorial of rice, 1/2 2^6 = 2x2x2x2x2x2. Two reps with 2 blocks in each rep.

Format

A data frame with 64 observations on the following 6 variables.

yield

grain yield in tons/ha

rep

replicate, 2 levels

block

block within rep, 2 levels

trt

treatment, levels (1) to abcdef

col

column position in the field

row

row position in the field

a

a treatment, 2 levels

b

b treatment, 2 levels

c

c treatment, 2 levels

d

d treatment, 2 levels

e

e treatment, 2 levels

f

f treatment, 2 levels

Details

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.

Examples

if (FALSE) {

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")


  # Ensure factors
  dat <- transform(dat,
                   a=factor(a), b=factor(b), c=factor(c),
                   d=factor(d), e=factor(e), f=factor(f) )
  
# 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")

}