What was the primal matter, what the substance?
How could it be discerned, how was it made?
From which the designer of all things, beholding all,
fashioned the earth and shaped the glory of the heavens?
-Rig Veda X, 81, 2.
The pages under this link describe the computer simulation of plasmas and their interaction with intense radiation using an algorithm known as the Particle-in-Cell method.
The following links have more details.
I will be adding, as and when time permits, descriptions of Electromgnetic techniques also.
The link below contains a PDF with notes on the solution of partial differential equations using finite-differences: