Fig. 3
From: Newton–Raphson preconditioner for Krylov type solvers on GPU devices
Convergence histories of each preconditioner on BCSSTK15. The vertical axis shows the residual norm \(\Vert \mathbf {r} \Vert _2 / \Vert \mathbf {b} \Vert _2\), and the horizontal axis shows the number of iterations. The plot is truncated at the 7500th iteration