Computes the revised modified Cholesky factorization described in Schnabel and Eskow (1999).
Usage
modifChol(x, tau = .Machine$double.eps^(1 / 3),
tau_bar = .Machine$double.eps^(2 / 3), mu = 0.1)
Value
Upper triangular matrix \(L\) of the form \(L'L = x + E\).
Arguments
x
a symmetric matrix.
tau
(machine epsilon)^(1/3).
tau_bar
(machine epsilon^(2/3)).
mu
numeric, \(0 < \mu \le 1\).
Author
Sheila Görz
Details
modif.chol computes the revised modified Cholesky Factorization of a symmetric, not necessarily positive definite matrix x + E such that \(L'L = x + E\) for \(E \ge 0\).
References
Schnabel, R. B., & Eskow, E. (1999). "A revised modified Cholesky factorization algorithm" SIAM Journal on optimization, 9(4), 1135-1148.