detectBifucation(state::ContState) always returns false after update v0.1.3 => v0.1.4

[gszep]

This is affecting BifurcationInference.jl is there a new default setting I am not aware of?

[rveltz]

At some point, I removed the computation of eigenvalues from the loop and put it in the iterator, maybe this is it: https://github.com/rveltz/BifurcationKit.jl/commit/cf5870368cc9a3ddc70a76eaea180c930e49d817

Can you display state.n_unstable and see if it is modified?

[gszep]

so its definitely already not working in 0.1.4 so I don't think its the commit you referenced. state.n_unstable along the branch looks like this

(1, 1)
(1, 1)
(1, 1)
(1, 1)
(1, 1)
(1, 1)
(0, 0)
(0, 0)
(0, 0)
(0, 0)
(0, 0)

[rveltz]

I guess you pass the option ContinuationPar.detectBifurcation=3? Where is your iterator loop so I can check it?

[gszep]

ah I pass detectBifurcation=true but passing detectBifurcation=3 doesn't change things. The loop is here https://github.com/gszep/BifurcationInference.jl/blob/036700f1524bcf8832ee9a948ab65e885be00519/src/BifurcationInference.jl#L109

[gszep]

hyperparameters::ContinuationPar is returned by https://github.com/gszep/BifurcationInference.jl/blob/036700f1524bcf8832ee9a948ab65e885be00519/src/Utils.jl#L2

[rveltz]

I think you can remove https://github.com/gszep/BifurcationInference.jl/blob/036700f1524bcf8832ee9a948ab65e885be00519/src/BifurcationInference.jl#L112 as it is in the iterator:

https://github.com/rveltz/BifurcationKit.jl/blob/master/src/Continuation.jl#L351

Then, you need to activate bifurcation detection as:

https://github.com/rveltz/BifurcationKit.jl/blob/master/src/Continuation.jl#L351

Did it really used to work that way?

[gszep]

in v0.1.3 the output of state.n_unstable used to be

(1, 1)
(1, 1)
(1, 1)
(1, 1)
(0, 1)
(0, 0)
(0, 0)
(0, 0)

so I guess the main difference is that there is no longer a transition state (0,1) in the new versions

[gszep]

also note that I have a push!(branch::Branch,state::ContState) method https://github.com/gszep/BifurcationInference.jl/blob/036700f1524bcf8832ee9a948ab65e885be00519/src/Structures.jl#L49

[rveltz]

I think it is because you have https://github.com/gszep/BifurcationInference.jl/blob/036700f1524bcf8832ee9a948ab65e885be00519/src/BifurcationInference.jl#L112

Try to remove it. Whenever you call computeEigenvalues!(iterator,state) it overwrite n_unstable. As I put this call in the iterator in 0.1.4, you call this function twice per continuation step and so bifurcations are undetected

[rveltz]

also note that I have a push!(branch::Branch,state::ContState) method https://github.com/gszep/BifurcationInference.jl/blob/036700f1524bcf8832ee9a948ab65e885be00519/src/Structures.jl#L49

this should not affect the detection

[gszep]

yep that did the trick thanks! I was not aware that computeEigenvalues!(iterator,state) was moved into the iterator (in v0.1.3 if I didn't have it in the loop explicitly it would not record stability info) and the new version makes much more sense 👍🏼

[rveltz]

Yeah, perhaps I should put the bifurcation detection in the iterator as well.