cochran.factorial {agridat}

Factorial experiment of beans, 2x2x2x2

Description

Factorial experiment of beans, 2x2x2x2.

Usage

data("cochran.factorial")

Format

A data frame with 32 observations on the following 4 variables.

rep

rep factor

block

block factor

trt

treatment factor, 16 levels

yield

yield (pounds)

d

dung treatment, 2 levels

n

nitrogen treatment, 2 levels

p

phosphorous treatment, 2 levels

k

potassium treatment, 2 levels

Details

Conducted by Rothamsted Experiment Station in 1936.

There were 4 treatment factors:

2 d dung levels: None, 10 tons/acre.

2 n nitrochalk levels: None, 0.4 hundredweight nitrogen per acre.

2 p superphosphate levels: None, 0.6 hundredweight per acre

2 k muriate of potash levels: None, 1 hundredweight K20 per acres.

The response variable is the yield of beans.

Source

Cochran, W.G. and Cox, G.M. (1957), Experimental Designs, 2nd ed., Wiley and Sons, New York, p. 160.

Examples

## Not run: 

library(agridat)
data(cochran.factorial)
dat <- cochran.factorial

# Ensure factors
dat <- transform(dat, d=factor(d), n=factor(n), p=factor(p), k=factor(k))

# Cochran table 6.5.
m1 <- lm(yield ~ rep * block + (d+n+p+k)^3, data=dat)
anova(m1)


libs(FrF2)
aliases(m1)
MEPlot(m1, select=3:6,
       main="cochran.factorial - main effects plot")


## End(Not run)