nlme (version 3.1-31)

qqnorm.lme: Normal Plot of Residuals or Random Effects from an lme Object

Description

Diagnostic plots for assessing the normality of residuals and random effects in the linear mixed-effects 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.

Usage

## S3 method for class 'lme':
qqnorm(y, form, abline, id, idLabels, grid, ...)

Value

a diagnostic Trellis plot for assessing normality of residuals or random effects.

See Also

lme, plot.lme

Examples

data(Orthodont)
fm1 <- lme(distance ~ age, Orthodont, random = ~ age | Subject)
# normal plot of standardized residuals by gender
qqnorm(fm1, ~ resid(., type = "p") | Sex, abline = c(0, 1))
# normal plots of random effects
qqnorm(fm1, ~ranef(.))