Nested static LabelledArrays: StackOverflowError

[JinraeKim]

solve with nested form of a static LabelledArray yields the StackOverflowError.
Here is the example:

• code

using Aerobatics
using OrdinaryDiffEq
using Plots
using LabelledArrays


function report()
    x0 = SLVector(x1=2, x2=3)
    ∫r0 = 0.0
    X0 = SLVector(x=x0, ∫r=∫r0)
    tspan = (0.0, 1.0)
    f = function (X, p, t)
        x, ∫r = X.x, X.∫r
        x1, x2 = x.x1, x.x2
        u = -x2
        dx1 = -(1/2)*x1^3 - x1 - 2*x2
        dx2 = (1/8)*x2^3 - x2 + (1/2)*u^3
        dx = SLVector(x1=dx1, x2=dx2)
        r = x1^4 + 2*(x1+x2)^2 + (3/4)*u^4
        SLVector(x=dx, ∫r=r)
    end
    prob = ODEProblem(f, X0, tspan)
    sol = solve(prob, Tsit5())
end

function test()
    report()
end

Run by test().

• Result

ERROR: StackOverflowError:
Stacktrace:
 [1] recursive_unitless_bottom_eltype(a::Type{Any}) (repeats 79984 times)
   @ RecursiveArrayTools ~/.julia/packages/RecursiveArrayTools/K3lTR/src/utils.jl:86

However, another similar example seems work as follows:

• code

function test2()
    _myvec = @SLVector (:a, :b)
    myvec = @SLVector (:x, :y)
    dynamics = function (X, p, t)
        dx = -X.x
        dy = -X.y
        myvec(dx, dy)
    end
    tspan = (0.0, 1.0)
    x = _myvec(1.0, 2.0)
    y = _myvec(1.0, 2.0)
    X = myvec(x, y)
    prob = ODEProblem(dynamics, X, tspan)
    sol = @time solve(prob, Tsit5())
end

• result

  5.121596 seconds (14.80 M allocations: 978.407 MiB, 3.39% gc time)
retcode: Success
Interpolation: specialized 4th order "free" interpolation
t: 5-element Vector{Float64}:
 0.0
 0.10001264591185442
 0.34206322751658697
 0.655359775820945
 1.0
u: 5-element Vector{SLArray{Tuple{2}, SLArray{Tuple{2}, Float64, 1, 2, (:a, :b)}, 1, 2, (:x, :y)}}:
 2-element SLArray{Tuple{2}, SLArray{Tuple{2}, Float64, 1, 2, (:a, :b)}, 1, 2, (:x, :y)} with indices SOneTo(2):
 :x => 2-element SLArray{Tuple{2}, Float64, 1, 2, (:a, :b)} with indices SOneTo(2):
 :a => 1.0
 :b => 2.0
 :y => 2-element SLArray{Tuple{2}, Float64, 1, 2, (:a, :b)} with indices SOneTo(2):
 :a => 1.0
 :b => 2.0
 2-element SLArray{Tuple{2}, SLArray{Tuple{2}, Float64, 1, 2, (:a, :b)}, 1, 2, (:x, :y)} with indices SOneTo(2):
 :x => 2-element SLArray{Tuple{2}, Float64, 1, 2, (:a, :b)} with indices SOneTo(2):
 :a => 0.9048259756770471
 :b => 1.8096519513540943
 :y => 2-element SLArray{Tuple{2}, Float64, 1, 2, (:a, :b)} with indices SOneTo(2):
 :a => 0.9048259756770471
 :b => 1.8096519513540943
 2-element SLArray{Tuple{2}, SLArray{Tuple{2}, Float64, 1, 2, (:a, :b)}, 1, 2, (:x, :y)} with indices SOneTo(2):
 :x => 2-element SLArray{Tuple{2}, Float64, 1, 2, (:a, :b)} with indices SOneTo(2):
 :a => 0.7103033089908293
 :b => 1.4206066179816585
 :y => 2-element SLArray{Tuple{2}, Float64, 1, 2, (:a, :b)} with indices SOneTo(2):
 :a => 0.7103033089908293
 :b => 1.4206066179816585
 2-element SLArray{Tuple{2}, SLArray{Tuple{2}, Float64, 1, 2, (:a, :b)}, 1, 2, (:x, :y)} with indices SOneTo(2):
 :x => 2-element SLArray{Tuple{2}, Float64, 1, 2, (:a, :b)} with indices SOneTo(2):
 :a => 0.5192552947803908
 :b => 1.0385105895607816
 :y => 2-element SLArray{Tuple{2}, Float64, 1, 2, (:a, :b)} with indices SOneTo(2):
 :a => 0.5192552947803908
 :b => 1.0385105895607816
 2-element SLArray{Tuple{2}, SLArray{Tuple{2}, Float64, 1, 2, (:a, :b)}, 1, 2, (:x, :y)} with indices SOneTo(2):
 :x => 2-element SLArray{Tuple{2}, Float64, 1, 2, (:a, :b)} with indices SOneTo(2):
 :a => 0.3678795934784995
 :b => 0.735759186956999
 :y => 2-element SLArray{Tuple{2}, Float64, 1, 2, (:a, :b)} with indices SOneTo(2):
 :a => 0.3678795934784995
 :b => 0.735759186956999

[JinraeKim]

If there is no way to deal with nested LabelledArrays, I would like to request the new feature for convenient numerical simulations.

[JinraeKim]

Maybe... related to #740 ?

[ChrisRackauckas]

I think you're looking for https://github.com/jonniedie/ComponentArrays.jl ?

[JinraeKim]

@ChrisRackauckas Thanks a lot! Very good!