Pendulum: make PendulumState as subtype of AbstractArray

[lilanger]

• added state() to import/export
• changed state from PendulumState type to array (easier to handle in advanced algorithms)
• shortened action annotation in plot

[iblislin]

changed state from PendulumState type to array (easier to handle in advanced algorithms)

How about keep PendulumState presented but just subtyped it from Vector{Float}, do this way help you handle in your algo? (Or solution 2: wirte some convert function for it.)

[lilanger]

It would be essential that env.state returns an Array instead of a PendulumState. I don't know how to do the subtyping though, I tried something like this but this is not valid:

mutable struct PendulumState{T<:Float64} <: Vector{Float64}
  θ::T
  θvel::T
  PendulumState(θ, θvel) = Float64[θ, θvel]
end

mutable struct Pendulum <: AbstractEnvironment
  state::Vector{Float64}
  reward::Float64
  a::Float64 # last action for rendering
  steps::Int
  maxsteps::Int
end

[iblislin]

ah, I guess the AbstractVector is the legit one.

[lilanger]

Nice, yes this seems to work.

[iblislin]

could you test the new patch?