degrees of freedom, i.e., number of random
regressors
rdist
random distribution function for sampling
args
arguments for rdist
nrow
number of rows in resulting matrix. This can
often be omitted in the context of functions like
lm where it is inferred from the data frame, if
one is provided.
seed
seed for random number generation
Value
A matrix of random variates with df columns. In
its intended use, the number of rows will be selected to
match the size of the data frame supplied to lm