An object returned by the lme
function, inheriting from class
lme
and representing a fitted linear mixedeffects
model. Objects of this class have methods for the generic functions
anova
, coef
, fitted
, fixed.effects
,
formula
, getGroups
, getResponse
,
intervals
, logLik
, pairs
, plot
,
predict
, print
, random.effects
, residuals
,
sigma
, summary
, update
, and vcov
.
The following components must be included in a legitimate lme
object.
an approximate covariance matrix for the
variancecovariance coefficients. If apVar = FALSE
in the
control values used in the call to lme
, this component is
NULL
.
a list containing an image of the lme
call that
produced the object.
a list with two components, fixed
and
random
, where the first is a vector containing the estimated
fixed effects and the second is a list of matrices with the estimated
random effects for each level of grouping. For each matrix in the
random
list, the columns refer to the random effects and the
rows to the groups.
a list with the contrasts used to represent factors in the fixed effects formula and/or random effects formula. This information is important for making predictions from a new data frame in which not all levels of the original factors are observed. If no factors are used in the lme model, this component will be an empty list.
a list with basic dimensions used in the lme fit,
including the components N
 the number of observations in
the data, Q
 the number of grouping levels, qvec

the number of random effects at each level from innermost to
outermost (last two values are equal to zero and correspond to the
fixed effects and the response), ngrps
 the number of groups
at each level from innermost to outermost (last two values are one
and correspond to the fixed effects and the response), and
ncol
 the number of columns in the model matrix for each
level of grouping from innermost to outermost (last two values are
equal to the number of fixed effects and one).
a data frame with the fitted values as columns. The leftmost column corresponds to the population fixed effects (corresponding to the fixed effects only) and successive columns from left to right correspond to increasing levels of grouping.
a list with components X
and terms
specifying the denominator degrees of freedom for, respectively,
ttests for the individual fixed effects and Ftests for the
fixedeffects terms in the models.
a data frame with the grouping factors as columns. The grouping level increases from left to right.
the (restricted) loglikelihood at convergence.
the estimation method: either "ML"
for maximum
likelihood, or "REML"
for restricted maximum likelihood.
an object inheriting from class lmeStruct
,
representing a list of mixedeffects model components, such
as reStruct
, corStruct
, and varFunc
objects.
the number of iterations used in the iterative algorithm.
a data frame with the residuals as columns. The leftmost column corresponds to the population residuals and successive columns from left to right correspond to increasing levels of grouping.
the estimated withingroup error standard deviation.
an approximate covariance matrix of the fixed effects estimates.
lme
, lmeStruct