modified-cholesky contains MATLAB functions that compute a modified Cholesky factorization of a symmetric and possibly indefinite matrix. The algorithm is from
S. H. Cheng and N.J. Higham. "A modified Cholesky algorithm based on a symmetric indefinite factorization". SIAM J. Matrix Anal. Appl., 19(4):1097-1110, 1998.

and uses LDL^T factorization with a symmetric form of rook pivoting proposed by Ashcraft, Grimes, and Lewis. The functions here are based on code originally written by Bobby Cheng and Nick Higham in 1996.