Latin square design in wheat — cochran.latin • agridat

Six wheat plots were sampled by six operators and shoot heights measured. The operators sampled plots in six ordered sequences. The dependent variate was the difference between measured height and true height of the plot.

Format

A data frame with 36 observations on the following 4 variables.

row: row
col: column
operator: operator factor
diff: difference between measured height and true height

Source

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

Examples

if (FALSE) { # \dontrun{

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

libs(desplot)
desplot(dat, diff~col*row,
        text=operator, cex=1, # aspect unknown
        main="cochran.latin")


dat <- transform(dat, rf=factor(row), cf=factor(col))
aov.dat <- aov(diff ~ operator + Error(rf*cf), dat)
summary(aov.dat)
model.tables(aov.dat, type="means")
} # }