Sparse matrix methods based on orthogonality and conjugacy
Charles L. Lawson · NASA STI Repository (National Aeronautics and Space Administration) · 1973
A matrix having a high percentage of zero elements is called spares. In the solution of systems of linear equations or linear least squares problems involving large sparse matrices, significant saving of computer cost can be achieved by taking advantage of the sparsity. The conjugate gradient algorithm and a set of related algorithms are described.