Dim.corStruct              package:nlme              R Documentation

Dimensions of a corStruct Object

Description:

     if 'groups' is missing, it returns the 'Dim' attribute of
     'object'; otherwise, calculates the dimensions associated with the
     grouping factor.

Usage:

     ## S3 method for class 'corStruct':
     Dim(object, groups, ...)

Arguments:

  object: an object inheriting from class 'corStruct', representing a
          correlation structure.

  groups: an optional factor defining the grouping of the observations;
          observations within a group are correlated and observations
          in different groups are uncorrelated.

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

Value:

     a list with components: 

       N: length of 'groups'

       M: number of groups

  maxLen: maximum number of observations in a group

sumLenSq: sum of the squares of the number of observations per group

     len: an integer vector with the number of observations per group

   start: an integer vector with the starting position for the
          observations in each group, beginning from zero

Author(s):

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

See Also:

     'Dim', 'Dim.corSpatial'

Examples:

     data(Orthodont)
     Dim(corAR1(), getGroups(Orthodont))

