column names from the pheno data of object
or a design matrix
Value
a design matrix
Details
Construct a design matrix
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.