Figure 4

Cost function V _b ( ϑ ) with respect to variables x ₄ , using sequence${\mathcal{T}}_{\mathbf{2}}\mathbf{=}\mathbf{\{}\mathbf{1}\mathbf{,}\mathbf{2}\mathbf{,}\mathbf{3}\mathbf{,}\mathbf{1}\mathbf{,}\mathbf{4}\mathbf{,}\mathbf{2}\mathbf{,}\mathbf{4}\mathbf{\}}$. Here, anchor nodes are denoted by crosses, the auxiliary node 4 is denoted by a triangle, and the passive receiving node N is denoted by an asterisk. (a) Batch size B = 1, batch index b = 4. (b) Batch size B = 3, batch index b = 2.