Fig. 2
From: Multilevel preconditioners for embedded enriched partition of unity approximations
Contour plots of the prolongation errors (left) attained for the constant function when using the weighted space \(\Phi _{\mathrm {HOST}} V_{\mathrm {HOST}}\) in the AMG construction of the prolongation \(P_{\mathrm {HOST}, J-1}^J\) for a small (top) and a large overlap region (bottom). Surface plots of the prolongation error of the smooth function \(\sin (3\pi x)\cos (3\pi y)\) using \(P_{\mathrm {HOST}, J-1}^J\) (center) and \(\bar{P}_{\mathrm {HOST}, J-1}^J\) (right)