An object to be coerced into a
Not used yet.
The dimensions of the
Grid object are matched to the d
columns of the object given in
object, in the same
order. Each column is coerced into a factor. Each combination
of the d different levels must be found exactly one in the
data frame or matrix, and the the row number of that combination is
stored in the
index slot of the object.
Object with S4 class
A numeric object is coerced into a
with dimension d =1.
1 2 3 4 5 6