Implementing non homogeneous euler equation

[Kundan Kumar]

Hi,

I am implementing nth order euler non homogeneous equation (homogeneous has already been implemented). But I am unable to understand what is key of "match" used in each function. From already implemented homogeneous euler equation, I got to know that match.keys also contain the order of each differential term (like shown in code below) along with the matching terms of type of ODEs.

for i in r.keys():

        if not isinstance(i, str) and i >= 0:

            chareq += (r[i]*diff(x**symbol, x, i)*x**-symbol).expand()

(this is for converting a differential eq to polynomial and then simplifying it by replacing f(x) by x**symbol, where symbol = Dummy('x'))

homogeneous eq:       a*x^2*f(x).diff(x,2) + b*x*f(x).diff(x) + c*f(x) = 0

non homogeneous eq: a*x^2*f(x).diff(x,2) + b*x*f(x).diff(x) + c*f(x) = g(x)

this is the code under "ode_nth_linear_euler_eq_homogeneous" under L3178

I am using the same code for non homogeneous but there I have extra g(x) term and I am unable to decide what r.keys() has in itself for g(x) as g(x) has x**(power) term.

[Aaron Meurer]

Did you figure this out?

Aaron Meurer

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[Kundan Kumar]

Yeah, I got it. Thanks