The yield of oats from a split-plot field trial using three varieties and four levels of manurial treatment. The experiment was laid out in 6 blocks of 3 main plots, each split into 4 sub-plots. The varieties were applied to the main plots and the manurial treatments to the sub-plots.
This data frame contains the following columns:
- Blocks, levels I, II, III, IV, V and VI.
- Varieties, 3 levels.
- Nitrogen (manurial) treatment, levels 0.0cwt, 0.2cwt, 0.4cwt and 0.6cwt, showing the application in cwt/acre.
- Yields in 1/4lbs per sub-plot, each of area 1/80 acre.
Venables, W. N. and Ripley, B. D. (2002) Modern Applied Statistics with S. Fourth edition. Springer.
oats$Nf <- ordered(oats$N, levels = sort(levels(oats$N))) oats.aov <- aov(Y ~ Nf*V + Error(B/V), data = oats, qr = TRUE) summary(oats.aov) summary(oats.aov, split = list(Nf=list(L=1, Dev=2:3))) par(mfrow = c(1,2), pty = "s") plot(fitted(oats.aov[]), studres(oats.aov[])) abline(h = 0, lty = 2) oats.pr <- proj(oats.aov) qqnorm(oats.pr[][,"Residuals"], ylab = "Stratum 4 residuals") qqline(oats.pr[][,"Residuals"]) par(mfrow = c(1,1), pty = "m") oats.aov2 <- aov(Y ~ N + V + Error(B/V), data = oats, qr = TRUE) model.tables(oats.aov2, type = "means", se = TRUE)