column names from the pheno data of
object or a design matrix
Value
a design matrix
Details
Make a design matrix from the pheno data slot of an
expression set, taking care that factors and numerical
are handled properly. No interactions are included and
formula is the most simple possible, i.e.
y~-1+term1+term2+.... Can also be given anything
as object in which case factor must be a design
matrix. It that case the same design matrix is returned.