# I am trying to run the tutorial code from 2019 of Differentiable-trebuchet, but got error in trying to find the gradient with ForwardDiff

(https://github.com/JuliaComputing/ODSC2019/blob/master/03-Differentiable-trebuchet-Zygote)

using Flux, Trebuchet

using Zygote: gradient, forwarddiff

## t = TrebuchetState()

simulate(t)

visualise(t)

function shoot(wind, angle, weight)

Trebuchet.shoot((wind, Trebuchet.deg2rad(angle), weight))[2]

end

shoot(ps) = forwarddiff(p → shoot(p…), ps)

gradient(shoot, [0, 45, 200])

## Error:

Cannot determine ordering of Dual tags ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, ForwardDiff.Dual{Nothing, Float64, 3}} and Nothing

This code, being published in 2019, my have been updated but I could not find it. Any help is much appreciated.