logLik                 package:base                 R Documentation

Extract Log-Likelihood

Description:

     This function is generic; method functions can be written to
     handle specific classes of objects.  Classes which already have
     methods for this function include: `lm', `nls' in package nls, and
     `gls', `lme' and others in package nlme.

Usage:

     logLik(object, ...)

     as.data.frame(x, row.names = NULL, optional = FALSE)

Arguments:

  object: any object from which a log-likelihood value, or a
          contribution to a log-likelihood value, can be extracted.

     ...: some methods for this generic function require additional
          arguments.

       x: an object of class `logLik'.

row.names, optional: arguments to the `as.data.frame' method; see its
          documentation.

Value:

     Returns an object, say `r', of class `logLik' which is a number
     with attributes, `attr(r, "df")' (degrees of freedom) giving the
     number of parameters in the model. There's a simple `print' method
     for `logLik' objects.

     The details depend on the method function used; see the
     appropriate documentation.

Author(s):

     Jose Pinheiro and Douglas Bates

See Also:

     `logLik.lm', `logLik.nls', `logLik.gls', `logLik.lme', etc.

Examples:

     ## see the method function documentation
     x <- 1:5
     lmx <- lm(x ~ 1)
     logLik(lmx) # using print.logLik() method
     str(logLik(lmx))

