logLik.lmList              package:nlme              R Documentation

Log-Likelihood of an lmList Object

Description:

     If 'pool=FALSE', the (restricted) log-likelihoods of the 'lm'
     components of 'object' are summed together. Else, the (restricted)
     log-likelihood of the 'lm' fit with different coefficients for
     each level of the grouping factor associated with the partitioning
     of the 'object' components is obtained.

Usage:

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

Arguments:

  object: an object inheriting from class 'lmList', representing a list
          of 'lm' objects with a common model. 

    REML: an optional logical value. If 'TRUE' the restricted
          log-likelihood is returned, else, if 'FALSE', the
          log-likelihood is returned. Defaults to 'FALSE'. 

    pool: an optional logical value indicating whether all 'lm'
          components of 'object' may be assumed to have the same error
          variance. Default is 'attr(object, "pool")'. 

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

Value:

     either the sum of the (restricted) log-likelihoods of each 'lm'
     component in 'object', or the (restricted) log-likelihood for the
     'lm' fit with separate coefficients for each component of
     'object'.

Author(s):

     Jose Pinheiro Jose.Pinheiro@pharma.novartis.com and Douglas Bates
     bates@stat.wisc.edu

See Also:

     'lmList', 'logLik.lme',

Examples:

     fm1 <- lmList(distance ~ age | Subject, Orthodont)
     logLik(fm1)   # returns NA when it should not

