Solver settings

These are the settings of the qpax solver:

Argument	Default	Backend	Description
backend	"i"	—	Selects the explicit ("e") or implicit retraction-manifold ("i") complementarity backend *.
solver_tol	1e-5	e, i	Stopping tolerance on the \(L_\infty\) norm of the KKT residual.
max_iter	30	e, i	Maximum number of iterations when solving the QP.
verbose	False	e, i	If True, prints per-iteration residual, step size, and centering info.
linear_solver	CHOLESKY	e	Factorization for the reduced KKT system (CHOLESKY or QR). Implicit backend always uses LU.
sigma	0.125	i	Centering parameter \(\sigma\) targeting the next duality gap. Accepted in e for API uniformity but unused (explicit uses Mehrotra centering).
target_kappa	1e-3	e, i	Relaxation parameter \(\kappa\) for the perturbed complementarity condition \(s \cdot z = \kappa\). Used only by relax_qp and solve_qp_primal.

* For further details on boths backends, see Algorithm.