Reinit `tdir` in ODEIntegrator

Specific Domains Modelling & Simulations
1

Hi @ChrisRackauckas , is there a way to change integration direction with reinit! when solving an ODE? Or the only way is to remake the ODEProblem?
E.g.:

using OrdinaryDiffEq

prob = ODEProblem((du, u, p, t) -> du[1] = 1.0, [0.], (0.,1.))

# right direction
integrator = init(prob, Tsit5())
reinit!(integrator; t0=0., tf=5.0)
solve!(integrator)
integrator.sol.t[end] 
# 5.0 correct

# left direction
integrator = init(prob, Tsit5())
reinit!(integrator; t0=0., tf=-5.0)
solve!(integrator)
integrator.sol.t[end] 
# 5.0 wrong
2

I don’t think there is. You can open an issue in OrdinaryDiffEq and we can see if we can get some integrators to handle that, but instead it might just be good to validate that it’s going the right direction.

3

Thanks! I’ve opened an issue: