Pull out selected phenotype data from a cross object, as a data frame or vector.
An object of class
A vector specifying which phenotypes to keep or discard. This may be a logical vector, a numeric vector, or a vector of character strings (for the phenotype names). If missing, the entire set of phenotypes is output.
A data.frame with columns specifying phenotypes and rows specifying individuals. If there is just one phenotype, a vector (rather than a data.frame) is returned.
Karl W Broman, firstname.lastname@example.org