cochran.beets {agridat} | R Documentation |
Yield and number of plants in a sugarbeet fertilizer experiment.
data("cochran.beets")
A data frame with 42 observations on the following 4 variables.
fert
fertilizer treatment
block
block
yield
yield (tons/acres)
plants
number of plants per plot
Yield (tons/acre) and number of beets per plot. Fertilizer treatments combine superphosphate (P), muriate of potash (K), and sodium nitrate (N).
George Snedecor (1946). Statisitcal Methods, 4th ed. Table 12.13, p. 332.
H. Fairfield Smith (1957). Interpretation of Adjusted Treatment Means and Regressions in Analysis of Covariance. Biometrics, 13, 282-308. http://doi.org/10.2307/2527917
data(cochran.beets) dat = cochran.beets # P has strong effect require(lattice) xyplot(yield ~ plants|fert, dat, main="cochran.beets")