make.groups {lattice}  R Documentation 
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.
make.groups(...)
... 
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. 
When all the input arguments are vectors, a data frame with two columns

all the vectors supplied, concatenated 

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.
Deepayan Sarkar Deepayan.Sarkar@Rproject.org
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"))