logLik.lme               package:nlme               R Documentation

Log-Likelihood of an lme Object

Description:

     If 'REML=FALSE', returns the log-likelihood value of the linear
     mixed-effects model represented by 'object' evaluated at the
     estimated  coefficients; else, the restricted log-likelihood
     evaluated at the estimated coefficients is returned.

Usage:

     ## S3 method for class 'lme':
     logLik(object, REML, ...)

Arguments:

  object: an object inheriting from class 'lme', representing a fitted
          linear mixed-effects model.

    REML: an optional logical value.  If 'TRUE' the restricted
          log-likelihood is returned, else, if 'FALSE', the
          log-likelihood is returned. Defaults to the method of
          esitmation used, that is 'TRUE' if and only 'object' was
          fitted with 'method = "REML"' (the default for these fitting
          functions) . 

     ...: some methods for this generic require additional arguments. 
          None are used in this method.

Value:

     the (restricted) log-likelihood of the model represented by
     'object' evaluated at the estimated coefficients.

Author(s):

     Jose Pinheiro and Douglas Bates

References:

     Harville, D.A. (1974) ``Bayesian Inference for Variance Components
     Using Only Error Contrasts'', _Biometrika_, *61*, 383-385.

     Pinheiro, J.C., and Bates, D.M. (2000) "Mixed-Effects Models in S
     and S-PLUS", Springer.

See Also:

     'lme','gls', 'logLik.corStruct', 'logLik.glsStruct',
     'logLik.lmeStruct', 'logLik.lmList', 'logLik.reStruct',
     'logLik.varFunc',

Examples:

     fm1 <- lme(distance ~ Sex * age, Orthodont, random = ~ age, method = "ML")
     logLik(fm1)
     logLik(fm1, REML = TRUE)

