Just a couple of physics notes: I wrote r as a scalar. This is the magnitude of the vector r.; The 1 over 4πε 0 is just a constant.; Electric potential is a scalar quantity, not a vector.

In plotly, for regular 2D graphs, the current format is that xaxis and yaxis have a subfield called title which is itself a dictionary/json object, and not a string. The title field used to be a ...