p>Returns the charge of the vertex,
the value of <a href="ForceDirectedVertex.html#charge" class="tsd-kind-accessor">ForceDirectedVertex.charge</a> if it&#39;s a number,
or else the value of <a href="ForceDirectedLayout.html#defaultElectricalCharge" class="tsd-kind-accessor">defaultElectricalCharge</a>.</p>
<p>The electrical forces between two vertexes decrease by the square of the distance between them.
Vertexes that are more than <a href="ForceDirectedLayout.html#infinityDistance" class="tsd-kind-accessor