gplot.lm: gplot diagnostics for an lm object

In raredd/plotr: More plotting functions and examples

gplot diagnostics for an lm object

Description

Six plots (selectable by which) are currently available: a plot of residuals against fitted values, a Scale-Location plot of sqrt(| residuals |) against fitted values, a Normal Q-Q plot, a plot of Cook's distances versus row labels, a plot of residuals against leverages, and a plot of Cook's distances against leverage/(1-leverage). By default, the first three and 5 are provided.

Usage

## S3 method for class 'lm'
gplot(
  x,
  which = c(1L:3L, 5L),
  grid = TRUE,
  col.grid = "grey90",
  col.acc = "white",
  caption = list("Residuals vs Fitted", "Normal Q-Q", "Scale-Location",
    "Cook's distance", "Residuals vs Leverage", expression("Cook's dist vs Leverage  " *
    h[ii]/(1 - h[ii]))),
  panel = if (add.smooth) panel.smooth else points,
  sub.caption = NULL,
  main = "",
  ask = prod(par("mfcol")) < length(which) && dev.interactive(),
  ...,
  id.n = 3,
  labels.id = names(residuals(x)),
  cex.id = 0.75,
  qqline = TRUE,
  cook.levels = c(0.5, 1),
  add.smooth = getOption("add.smooth"),
  label.pos = c(4, 2),
  cex.caption = 1
)

Arguments

x	lm object, typically result of lm or glm.
which	a subset of the numbers 1:6, by default 1:3, 5, referring to "Residuals vs Fitted", aka ‘Tukey-Anscombe’ plot "Normal Q-Q" plot, an enhanced qqnorm(resid(.)) "Scale-Location" "Cook's distance" "Residuals vs Leverage" "Cook's dist vs Lev./(1-Lev.)" See also ‘Details’ below.
grid	logical; if TRUE, a background grid will be drawn
col.grid	grid color
col.acc	grid accent color
caption	captions to appear above the plots; character vector or list of valid graphics annotations, see as.graphicsAnnot, of length 6, the j-th entry corresponding to which[j], see also the default vector in ‘Usage’. Can be set to "" or NA to suppress all captions.
panel	panel function. The useful alternative to points, panel.smooth can be chosen by add.smooth = TRUE.
sub.caption	common title—above the figures if there are more than one; used as sub (s.title) otherwise. If NULL, as by default, a possible abbreviated version of deparse(x$call) is used.
main	title to each plot—in addition to caption.
ask	logical; if TRUE, the user is asked before each plot, see par(ask=.).
...	other parameters to be passed through to plotting functions.
id.n	number of points to be labelled in each plot, starting with the most extreme.
labels.id	vector of labels, from which the labels for extreme points will be chosen. NULL uses observation numbers.
cex.id	magnification of point labels.
qqline	logical indicating if a qqline() should be added to the normal Q-Q plot.
cook.levels	levels of Cook's distance at which to draw contours.
add.smooth	logical indicating if a smoother should be added to most plots; see also panel above.
label.pos	positioning of labels, for the left half and right half of the graph respectively, for plots 1-3, 5, 6.
cex.caption	controls the size of caption.

raredd/plotr documentation built on Nov. 19, 2023, 4:09 a.m.