snpdata: Class for SNP genotype and phenotype data.
Description
Objects of this class contain subject-specific SNP genotype or allele
dosage data along with subject-specific phenotypes data, and SNP
coded/noncoded allele information.
An object of class snpdata is a list with at least two elements, called
snpinfo and data. snpdata$snpinfo must be a data frame
with (at least) columns called snp, coded.allele and noncoded.allele.
snpdata$data must be a data frame with columns for each SNP in
snpdata$snpinfo with column names formed by pasting together the
snp and coded.allele with a separating underscore character,
e.g. rs12345_A.