@TECHREPORT\{IMM2004-03173,
    author       = "B. S. Andersen and J. A. Gunnels and F. G. Gustavson and J. K. Reid and J. Wasniewski",
    title        = "A Fully Portable High Performance Minimal Storage Hybrid Format Cholesky Algorithm",
    year         = "2004",
    keywords     = "real symmetric matrices, complex Hermitian matrices, positive definite matrices, Cholesky factorization and solution, recursive algorithms, novel packed matrix data structures, linear systems of equations",
    number       = "",
    series       = "IMM-Technical Report-2004-9",
    institution  = "Informatics and Mathematical Modelling, Technical University of Denmark, {DTU}",
    address      = "Richard Petersens Plads, Building 321, {DK-}2800 Kgs. Lyngby",
    type         = "",
    url          = "http://www2.compute.dtu.dk/pubdb/pubs/3173-full.html",
    abstract     = "We consider the eficient implementation of the Cholesky solution of symmetric positive-definite dense linear systems of equations using packed storage. We take the same starting point as that of {LINPACK} and {LAPACK,} with the upper (or lower) triangular part of the matrix being stored by columns. Following {LINPACK} and {LAPACK,} we overwrite the given matrix by its Cholesky factor. We consider the use of a hybrid format in which blocks of the matrices are held contiguously and compare this to the present {LAPACK} code. Code based on this format has the storage advantages of the present code, but substantially outperforms it. Furthermore, it compares favourably to using conventional full format (LAPACK) and using the recursive format of Andersen, Gustavson, and Wasniewski."
}