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- 04:12ChrisRackauckas commented #181
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- 03:56ChrisRackauckas edited #182
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- 03:13danielchen26 commented #509
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- 02:47JuliaRegistrator commented #73
- 02:47ChrisRackauckas commented #73
- 02:47
ChrisRackauckas on master

Update Project.toml (compare)

- 02:47
ChrisRackauckas on nondiag

- 02:46
ChrisRackauckas on master

fix non-diagonal noise variable… Merge pull request #76 from Jul… (compare)

- 02:46ChrisRackauckas closed #76

[slack] <chrisrackauckas> depends, 1D can be hard depending on the nonlinearities

[slack] <Antoine Levitt> I thinks he just wants linear Schrödinger

[slack] <Antoine Levitt> 1d is pretty forgiving, if you just want to plot something

[slack] <Antoine Levitt> For more advanced methods I'd do a splitting with an FFT to solve the kinetic term

[slack] <david.plankensteiner> @mason.protter Are you looking to do something like this: https://qojulia.org/documentation/examples/particle-into-barrier.html ?

[slack] <chrisrackauckas> I wonder if a small change of the working CNF would give a working FFJORd

[slack] <pihop> Hi, I ran into a problem with the coupling of VariableRateJump with SDEs again. The following mwe

```
using DifferentialEquations
function ff(du,u,p,t)
if p == 0
du .= 1.01u
else
du .= 2.01u
end
end
function gg(du,u,p,t)
du[1,1] = 0.1u[1]
du[1,2] = 0.1u[1]
du[2,1] = 0.2u[1]
du[2,2] = 0.2u[2]
end
rate_switch(u,p,t) = u[1]
function affect_switch!(integrator)
integrator.p = 1
end
jump_switch = VariableRateJump(rate_switch,affect_switch!)
prob = SDEProblem(ff,gg,ones(2),(0.0,1.0),0,noise_rate_prototype=zeros(2,2))
jump_prob = JumpProblem(prob, Direct(), jump_switch)
sol = solve(EnsembleProblem(jump_prob), EM(), dt = 0.01; trajectories=10)
timepoint_meanvar(sol, 0.1)
```

gives an error `MethodError: no method matching __broadcast`

when calling the `timepoint_meanvar`

. Evaluating it on the boundaries t=0 and t=1 works. The error has the cascade effect of breaking EnsembleSummary when VariableRateJumps are involved. Any ideas what is going wrong? Should this be reported to DiffEqBase or somewhere else?

[slack] <chrisrackauckas> this is... oh god this one might be more difficult 🙂

[slack] <chrisrackauckas> Turn it into arrays first

[slack] <chrisrackauckas> the problem is that when you are doing variable rate jumps they are arrays with a bunch of other hidden things.

[slack] <chrisrackauckas> If you just loop it would be fine.

[slack] <pihop> I see. Makes sense, thanks 🙂

[slack] <adam.jozefiak> @chrisrackauckas I'm fixing up the (pure) upwind operators for DiffEqOperators and I just have a question with regards to stencil lengths with respect to derivative order and approximation.

1) For interior stencils, is the the stencil length simply: derivative_order + approximation_order ?

2) For boundary stencils, such as the case where we have a forward difference near the upper boundary and it is clear that a pure upwind will not fit, what should the stencil length be? Is it still derivative_order + approximatio_order?

1) For interior stencils, is the the stencil length simply: derivative_order + approximation_order ?

2) For boundary stencils, such as the case where we have a forward difference near the upper boundary and it is clear that a pure upwind will not fit, what should the stencil length be? Is it still derivative_order + approximatio_order?

[slack] <adam.jozefiak> For instance, I obtain the concretization of the second order approximation of the first derivative operator on a three interior node grid, with positive coefficients as:

`[ 0.0, -1.5, 2.0, -0.5, 0.0 ]`

`[ 0.0, 0.0, -1.5, 2.0, -0.5 ]`

`[ 0.0, 0.0, -0.5, 0.0, 0.5 ]`

[slack] <chrisrackauckas> I am not sure.

[slack] <chrisrackauckas> but looks like it could work

[slack] <chrisrackauckas> There's a dispatch of

`ldiv!`

on a QR that is broken on 1.1 IIRC
[slack] <chrisrackauckas> https://github.com/JuliaDiffEq/DifferentialEquations.jl/issues/469#issuecomment-533542895

[slack] <chen.tianc> I am trying to use Parallel Ensemble simulation for SDE using Gillespie. But I got error

```
julia> solve(ensemble_prob,SSAStepper(),trajectories=10)
ERROR: Inappropiate solve command. The arguments do not make sense. Likely, you gave an algorithm which does not actually exist (or does not <:DiffEqBase.DEAlgorithm)
```

. if I want to randomize both initial condition and parameters, how should I write `prob_func`

?
[slack] <chrisrackauckas> see if you are fine with that

[slack] <chen.tianc> I just tried for ode case. Am I doing something wrong?

[slack] <chrisrackauckas>

`EnsembleSerial()`

[slack] <chen.tianc> it show

`ERROR: type JumpProblem has no field u0`

using the first `prob_func`

and `ERROR: type JumpProblem has no field f`

using the second `prob_func`

[slack] <chrisrackauckas> okay, open an issue with this MWE

[slack] <chrisrackauckas> I'll get to it after some Pumas stuff.

[slack] <chen.tianc> ok, thanks