Calculate the Poynting Vector

The Poynting vector, which is the directional flux of the electromagnetic fields, defined by \begin{equation} \mathbf{S}=\frac{1}{\mu_0}\mathbf{E}\times\mathbf{B}, \end{equation} can be calculated in PyCharge along a grid by simply calculating \(\mathbf{E}\) and \(\mathbf{B}\) and then performing the cross product. An example is shown in Figure 5 in the PyCharge paper, and the corresponding script is given in examples/paper_figures/figure5.py: