Plot a gls Object
Diagnostic plots for the linear model fit are obtained. The
form argument gives considerable flexibility in the type of
plot specification. A conditioning expression (on the right side of a
| operator) always implies that different panels are used for
each level of the conditioning factor, according to a Trellis
display. If form is a one-sided formula, histograms of the
variable on the right hand side of the formula, before a |
operator, are displayed (the Trellis function histogram is
used). If form is two-sided and both its left and
right hand side variables are numeric, scatter plots are displayed
(the Trellis function xyplot is used). Finally, if form
is two-sided and its left had side variable is a factor, box-plots of
the right hand side variable by the levels of the left hand side
variable are displayed (the Trellis function bwplot is used).
## S3 method for class 'gls' plot(x, form, abline, id, idLabels, idResType, grid, ...)
x |
an object inheriting from class |
form |
an optional formula specifying the desired type of
plot. Any variable present in the original data frame used to obtain
|
abline |
an optional numeric value, or numeric vector of length two. If given as a single value, a horizontal line will be added to the plot at that coordinate; else, if given as a vector, its values are used as the intercept and slope for a line added to the plot. If missing, no lines are added to the plot. |
id |
an optional numeric value, or one-sided formula. If given as
a value, it is used as a significance level for a two-sided outlier
test for the standardized residuals. Observations with
absolute standardized residuals greater than the 1 - value/2
quantile of the standard normal distribution are identified in the
plot using |
idLabels |
an optional vector, or one-sided formula. If given as a
vector, it is converted to character mode and used to label the
observations identified according to |
idResType |
an optional character string specifying the type of
residuals to be used in identifying outliers, when |
grid |
an optional logical value indicating whether a grid should
be added to plot. Default depends on the type of Trellis plot used:
if |
... |
optional arguments passed to the Trellis plot function. |
a diagnostic Trellis plot.
José Pinheiro and Douglas Bates bates@stat.wisc.edu
fm1 <- gls(follicles ~ sin(2*pi*Time) + cos(2*pi*Time), Ovary,
correlation = corAR1(form = ~ 1 | Mare))
# standardized residuals versus fitted values by Mare
plot(fm1, resid(., type = "p") ~ fitted(.) | Mare, abline = 0)
# box-plots of residuals by Mare
plot(fm1, Mare ~ resid(.))
# observed versus fitted values by Mare
plot(fm1, follicles ~ fitted(.) | Mare, abline = c(0,1))Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.