Plot Components + Residuals for Two Factors
For an analysis of variance or regression with (at least) two factors: Plot components + residuals for two factors according to Tukey's “forget-it plot”. Try it!
compresid2way(aov, data=NULL, fac=1:2, label = TRUE, numlabel = FALSE,
xlab=NULL, ylab=NULL, main=NULL,
col=c(2,3,4,4), lty=c(1,1,2,4), pch=c(1,2))aov |
either an |
data |
data frame containing |
fac |
the two factors used for plotting. Either column numbers or
names for argument |
label |
logical indicating if levels of factors should be shown in the plot. |
numlabel |
logical indicating if effects of factors will be shown in the plot. |
xlab,ylab,main |
the usual |
col,lty,pch |
colors, line types, plotting characters to be used
for plotting [1] positive residuals, [2] negative residuals,
[3] grid, [4] labels. If |
For a two-way analysis of variance, the plot shows the additive components of the fits for the two factors by the intersections of a grid, along with the residuals. The observed values of the target variable are identical to the vertical coordinate.
The application of the function has been extended to cover more complicated models. The components of the fit for two factors are shown as just described, and the residuals are added. The result is a “component plus residual” plot for two factors in one display.
Invisibly, a list with components
compy |
data.frame containing the component effects of the two factors, and combined effects plus residual |
coef |
coefficients: Intercept and effects of the factors |
Werner Stahel stahel@stat.math.ethz.ch
F. Mosteller and J. W. Tukey (1977) Data Analysis and Regression: A Second Course in Statistics. Addison-Wesley, Reading, Mass., p. 176.
John W. Tukey (1977) Exploratory Data Analysis. Addison-Wesley, Reading, Mass., p. 381.
## From Venables and Ripley (2002) p.165.
N <- c(0,1,0,1,1,1,0,0,0,1,1,0,1,1,0,0,1,0,1,0,1,1,0,0)
P <- c(1,1,0,0,0,1,0,1,1,1,0,0,0,1,0,1,1,0,0,1,0,1,1,0)
K <- c(1,0,0,1,0,1,1,0,0,1,0,1,0,1,1,0,0,0,1,1,1,0,1,0)
yield <- c(49.5,62.8,46.8,57.0,59.8,58.5,55.5,56.0,62.8,55.8,69.5,55.0,
62.0,48.8,45.5,44.2,52.0,51.5,49.8,48.8,57.2,59.0,53.2,56.0)
npk <- data.frame(block=gl(6,4), N=factor(N), P=factor(P),
K=factor(K), yield=yield)
npk.cr <- compresid2way(yield ~ N+P+K, data=npk, fac=c("P","K"))
## Fisher's 1926 data on potatoe yield
data(potatoes)
pot.aov <- aov(yield ~ nitrogen+potash+pos, data=potatoes)
compresid2way(pot.aov, pch=as.character(potatoes$pos))
compresid2way(yield~nitrogen+potash, data=subset(potatoes, pos == 2))
## 2 x 3 design :
data(warpbreaks)
summary(fm1 <- aov(breaks ~ wool + tension, data = warpbreaks))
compresid2way(fm1)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.