logLik.lmList {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`

### Examples

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

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