I am doing multi scale analysis while solving a particular nonlinear PDE. I am trying to check a solution I have for a particular set of boundary conditions and governing equation, to a given order.
Is there a simple way to sort scales on Mathematica? For example, if our small parameter is a, and I just want to check the O(a^3) solution, is there a way I can have Mathematica set all higher oder terms to zero? Manual inspection could work, but my equations are complex and my output is ~ 75 pages.
Any help is appreciated!