computed from MAF matrix P matrix Philippe Rocca-Serra P matrix is a kind of genomic relationship matrix which contains allele frequencies expressed as a difference from 0.5 and multiplied by 2. http://articles.extension.org/pages/68019/genomic-relationships-and-gblup Efficient Methods to Compute Genomic Predictions. J. Dairy Sci. 91:4414-4423. 2008 P. M. VanRaden. 10.31 68/jds.2007-0980 matrix ready for release