如何用边界条件求解微分方程，其中之一是使用python的不等式

Question

It is possible to set a boundary condition like psi(z>L)< eps ?

I have a system:

dD/dz = ....  
dPsi/dz = ....   

And boundary conditions:

D(0) = 1,6*Pi  
Psi(z>L) < eps

I read about scipy.integrate.solve_bvp and odeint , but all examples have boundary conditions like: y(0) = y(1) = 0

Does anyone know how to set such condition?

Answer 1

It would be easier to answer, if you provided a bit more info about the problem. If I understand correctly, L is the limit of your integration, so the boundary condition is actually

Psi(L)=eps

In case you integrate beyond L, you will probably need to have a condition to check on each iteration (new point, etc). Something along the lines:

if z>L and Psi(z)>=eps:
    do the action

What this action should be would depend on the problem. Hope this helps.