[SciPy-User] Understanding the "vode" warning for `scipy.integrate.ode`: "This integrator is not re-entrant. You cannot have two ode instances...at the same time."

[Pauli Virtanen]

13.05.2015, 04:33, Brian Merchant kirjoitti:
> I'd like to make sure I am understanding the warning for the "vode" and
> "zvode" integrators, provided by `scipy.integrate.ode` correctly -- it
> might seem repetitive, but please bear with me.

(i) The warning applies only to scipy.integrate.ode when using
vode/zvode. It does not apply to scipy.integrate.odeint or the other
solvers available in scipy.integrate.ode.

(ii) It is not possible to do this: solve first one problem, then switch
to a second problem, and then switch back to the first one. The solver
has only a single process-wide opaque internal state that can only hold
one problem at a time.

(iii) Where the limitation comes from in practice is that the VODE/ZVODE
solvers use many global variables; the code is fairly old Fortran, and
is not that easily refactored.