DifferentialEquations.jl OrwenZen5 not defined

question

#1

Hi. I recently started using Julia. I’m currently trying to simulate a Mackey-Glass chaotic time-series with DifferentialEquations.jl.

The package documentation advises the use of a solver OrwenZen5() for solving delay differential equations. But trying to use this I find that neither OrwenZen5 nor OrwenZen3 are defined. I am able to use other solvers with the MethodOfSteps such as those recommended for standard ODEs. I don’t know if these solvers were removed but the documentation wasn’t updated or what happened…

PS: I have little experience with delay differential equations, I was simply trying to reproduce a paper that used this time-series as a benchmark for some estimation algorithms. As such I would greatly appreciate any tips you might have on what the most appropriate solver is.


#2

Can you post your Pkg.status("DifferentialEquations"); Pkg.status("OrdinaryDiffEq")? My guess is you’re on an old version, and this will tell me what version you have.

It used to, but that’s no longer true. I would suggest Tsit5() or Vern6() depending on the tolerance you need. Of course, we should get you an up to date version first though.

BTW, this equation is one of the ones we use to benchmark the solvers.

and it’s defined here:


#3

Wow, thanks for the prompt response.

I went back to the documentation at http://docs.juliadiffeq.org/latest/tutorials/dde_example.html at it does recommend Tsit5 or Vern6 now :stuck_out_tongue: I dunno if it was changed in the meanwhile or maybe I was looking at a cached version…

I had already tried using Tsit5 before and it worked great, I was just worried about whether that integrator wasn’t the most appropriate.

Looking at the notebook helped me figure out the problem though. It is OwrenZen5 and not OrwenZen5. I think I might have copied it wrong from the tutorial.

Thanks a lot for your help :slight_smile: