cochran.lattice {agridat} | R Documentation |

##
Balanced lattice experiment in cotton

### Description

Balanced lattice experiment in cotton

### Usage

data("cochran.lattice")

### Format

A data frame with 80 observations on the following 5 variables.

`y`

percent of affected flower buds

`rep`

replicate

`row`

row

`col`

column

`trt`

treatment factor

### Details

The experiment is a balanced lattice square with 16 treatments in a 4x4
layout in each of 5 replicates. The treatments were applied to cotton
plants. Each plot was ten rows wide by 70 feet long
(about 1/18 of an acre). (Estimated plot width is 34.5 feet.)
Data were collected from the middle 4 rows.
The data are the percentages of squares showing attack by boll weevils.
A 'square' is the name given to a young flower bud.

The plot orientation is not clear.

### Source

William G. Cochran, Gertrude M. Cox. *Experimental Designs*, 2nd
Edition. Page 490.

Originally from: F. M. Wadley (1946).
Incomplete block designs in insect population problems.
*J. Economic Entomology*, 38, 651–654.

### References

Walter Federer.
Combining Standard Block Analyses With Spatial Analyses Under a Random
Effects Model. Cornell Univ Tech Report BU-1373-MA.
https://hdl.handle.net/1813/31971

### Examples

## Not run:
library(agridat)
data(cochran.lattice)
dat <- cochran.lattice
libs(desplot)
desplot(dat, y~row*col|rep,
text=trt, # aspect unknown, should be 2 or .5
main="cochran.lattice")
# Random rep,row,column model often used by Federer
libs(lme4)
dat <- transform(dat, rowf=factor(row), colf=factor(col))
m1 <- lmer(y ~ trt + (1|rep) + (1|rep:row) + (1|rep:col), data=dat)
summary(m1)
## End(Not run)

[Package

*agridat* version 1.18

Index]