Inverse of a Matrix of Relationships Due to Sires and Maternal Grandsires in an Inbred Population

Abstract

A rapid method for computing the inverse of the numerator relationship matrix, A, and the diagonals of A using sires and maternal grandsires in an inbred population is presented. Computer storage requirements are only four vectors of length equal to the number of animals in the system. About 1 h was required for an IBM 370/135 to carry out these computations on a population of approximately 5000 individuals.