M. Tuma and J. Scott, HSL_MI30 Symmetric indefinite saddle-point systems: incomplete indefinite factorization, HSL 2014. HSL_MI30 - the signed incomplete Cholesky factorization code. You can obtain the files here.
M. Tuma and J. Scott, The incomplete Cholesky factorization code (9.12.2013). HSL_MI28 computes an incomplete Cholesky factorization of a sparse symmetric matrix A that may be used as a preconditioner. You can obtain the files here.
M. Tuma and J. Scott, HSL_MI30 Symmetric indefinite saddle-point systems: incomplete indefinite factorization, HSL 2014. HSL_MI30 - the signed incomplete Cholesky factorization code. You can obtain the files