p.res.2fact {sfsmisc}R Documentation

Plot Numeric (e.g. Residuals) vs 2 Factors Using Boxplots

Description

Plots a numeric (``residual like'') variable against two factor covariates, using boxplots.

Usage

p.res.2fact(x, y, z, restricted, notch = FALSE,
            xlab = NULL, ylab = NULL, main = NULL)

Arguments

x,y two factors or numeric vectors giving the levels of factors.
z numeric vector of same length as x and y, typically residuals.
restricted positive value which truncates the size. The corresponding symbols are marked by stars.
notch logical indicating if the boxplots should be notched, see boxplot(*,notch).
xlab,ylab axis labels, see plot.default, per default the actual argument expressions.
main main title passed to plot.

Details

if values are restricted, this make use of the auxiliar function u.boxplot.x.

Author(s)

Lorenz Gygax logyg@wild.unizh.ch and Martin Maechler, Jan.95; starting from p.res.2x().

See Also

p.res.2x, boxplot, plot.lm, TA.plot.

Examples

I <- 8; J <- 3; K <- 20
xx <- factor(rep(rep(1:I, rep(K,I)),J))
yy <- factor(rep(1:J, rep(I*K,J)))
zz <- rt(I*J*K, df=5) #-- Student t with 5 d.f.
p.res.2fact(xx,yy,zz, restr= 4, main= "i.i.d. t <- 5 random  |.| <= 4")
mtext("p.res.2fact(xx,yy,zz, restr= 4, ..)",
      line=2, adj=1, outer=TRUE, cex=1)

## Real data
data(warpbreaks)
(fm1 <- lm(breaks ~ wool*tension, data = warpbreaks))
with(warpbreaks,
     p.res.2fact(wool, tension, residuals(fm1)))

[Package Contents]