[SciPy-user] integrate.odeint , stiff chemical equations and mass conservation -any hint?

[ms]

Joshua Stults ha scritto:
> I think the standard way to "fix" stiff problems is to go to implicit
> time-stepping.
> 
> Here's a nice write-up about using implicit time-stepping for chemical kinetics:
> http://www.osti.gov/bridge/servlets/purl/45627-eDTnun/webviewable/45627.pdf
> 
> It's over a decade old, but might give you some hints on how to solve
> your problem.
> 
> If you are integrating the system accurately you should be conserving
> mass, even with big implicit time-steps, your production and loss
> terms should balance at each step.

I'm confused, this thing is getting much worse than I could imagine.
Does it mean I have to rewrite the integrator myself and that odeint is
not good in this case?

I would use CHEMSODE, but it seems unavailable on the web, I only can
find the paper.

I'll give a spin to pydstool, then let's see...

m.