Defines a class for variant call format data.
A vcfR object contains three slots.
The first slot is a character vector which holds the meta data.
The second slot holds an eight column matrix to hold the fixed data.
The third slot is a matrix which holds the genotype data.See vignette('vcf_data') for more information.
See the http://samtools.github.io/hts-specs/{vcf specification} for the file specification.