make.groups             package:lattice             R Documentation

Grouped data from multiple vectors

Description:

     Combines two or more vectors, possibly of different lengths,
     producing a data frame with a second column indicating which of
     these vectors that row came from.  This is mostly useful for
     getting data into a form suitable for use in high level Lattice
     functions.

Usage:

     make.groups(...)

Arguments:

     ...: one or more vectors of the same type (coercion is attempted
          if not), or one or more data frames with similar columns,
          with possibly differing number of rows. 

Value:

     When all the input arguments are vectors, a data frame with two
     columns 

  'data': all the vectors supplied, concatenated 

 'which': factor indicating which vector the corresponding 'data' value
          came from 

     When all the input arguments are data frames, the result of
     'cbind' applied to them, along with an additional 'which' column
     as described above.

Author(s):

     Deepayan Sarkar Deepayan.Sarkar@R-project.org

See Also:

     'Lattice'

Examples:

     sim.dat <-
         make.groups(uniform = runif(200),
                     exponential = rexp(175),
                     lognormal = rlnorm(150),
                     normal = rnorm(125))
     qqmath( ~ data | which, sim.dat, scales = list(y = "free"))

