Fig. 1.

The worst-case performance of the sequence ${\left\{{\mathit{x}}_i\right\}}_{i=0}^N$ of GM with an optimal fixed-step h_opt(N) for N = 2, 5 and d = L = R = 1. The numerically optimized fixed-step sizes for N = 2, 5 are h_opt(2) = 1.6058 and h_opt(5) = 1.7471 [9].