Case Study: Singular Perturbation Theory with SymPy

[Philipp Janert]

As promised a few days ago, I did write up my "case study"

on doing singular perturbation theory with SymPy:

https://janert.me/guides/case-study-singular-perturbation-theory-with-sympy/

The idea here is to offload some very tedious and 

cumbersome algebra to SymPy. In the end, I managed

to automate it fully, to the point that I now have a SymPy

program that will generate new terms in a perturbation

expansion by itself, without human intervention. 

The script is at the end of the blog post linked above.

And, for what it's worth: to extract "pieces of expressions"

(which was my original question), I don't use SymPy features

directly, but instead rely on an algebraic identity. Which worked

in this case, because I knew the form of the terms for this 

problem.

Best,

  Ph.