Recently, I came across the article "SAGE off Stage: Teaching Electromagnetics with a Symbolic Computation Tool" by Yumin Zhang, David K. Probst. I was wondering, are there any other similar resources? It would be great if it demonstrates plotting electric fields, equipotential surfaces etc.
Others:
http://matematicas.uam.es/~fernando.chamizo/dark/d_electr.html
https://ernestyalumni.wordpress.com/2016/05/31/electromagnetism/