Demo not running

[flmuk]

Hello,
I am trying to run the example https://docs.sciml.ai/NeuralPDE/stable/tutorials/pdesystem/, on a newly created Julia project.

using NeuralPDE, Lux, Optimization, OptimizationOptimJL
import ModelingToolkit: Interval

@parameters x y
@variables u(..)
Dxx = Differential(x)^2
Dyy = Differential(y)^2

# 2D PDE
eq = Dxx(u(x, y)) + Dyy(u(x, y)) ~ -sin(pi * x) * sin(pi * y)

# Boundary conditions
bcs = [u(0, y) ~ 0.0, u(1, y) ~ 0.0,
    u(x, 0) ~ 0.0, u(x, 1) ~ 0.0]
# Space and time domains
domains = [x ∈ Interval(0.0, 1.0),
    y ∈ Interval(0.0, 1.0)]

# Neural network
dim = 2 # number of dimensions
chain = Lux.Chain(Dense(dim, 16, Lux.σ), Dense(16, 16, Lux.σ), Dense(16, 1))

# Discretization
dx = 0.05
discretization = PhysicsInformedNN(chain, GridTraining(dx))

@named pde_system = PDESystem(eq, bcs, domains, [x, y], [u(x, y)])
prob = discretize(pde_system, discretization)

#Optimizer
opt = OptimizationOptimJL.BFGS()

#Callback function
callback = function (p, l)
    println("Current loss is: $l")
    return false
end

res = Optimization.solve(prob, opt, callback = callback, maxiters = 1000)
phi = discretization.phi

using Plots

xs, ys = [infimum(d.domain):(dx / 10):supremum(d.domain) for d in domains]
analytic_sol_func(x, y) = (sin(pi * x) * sin(pi * y)) / (2pi^2)

u_predict = reshape([first(phi([x, y], res.u)) for x in xs for y in ys],
                    (length(xs), length(ys)))
u_real = reshape([analytic_sol_func(x, y) for x in xs for y in ys],
                 (length(xs), length(ys)))
diff_u = abs.(u_predict .- u_real)

p1 = plot(xs, ys, u_real, linetype = :contourf, title = "analytic");
p2 = plot(xs, ys, u_predict, linetype = :contourf, title = "predict");
p3 = plot(xs, ys, diff_u, linetype = :contourf, title = "error");
plot(p1, p2, p3)

I created the project by running ] activate .; add NeuralPDE.

I use Julia Version 1.8.5
Commit 17cfb8e65ea (2023-01-08 06:45 UTC)

Here is the output I get when running ] st -m: pstatus.txt

When running the above mentioned example, I get the following error when executing
res = Optimization.solve(prob, opt, callback = callback, maxiters = 1000):
ERROR: ArgumentError: The passed automatic differentiation backend choice is not available. Please load the corresponding AD package Zygote. (see here for the full stack trace:
errmsg.txt)

What can I do? Although the tutorial says that the code is copy-pastable, for me it just won't run. I also tried running ] add Zygote, but that didn't work either.

EDIT:

When running using NeuralPDE, Lux, Optimization, OptimizationOptimJL I get

┌ Warning: Error requiring `Zygote` from `Optimization`
│   exception =
│    LoadError: ArgumentError: Package Optimization does not have Zygote in its dependencies:
│    - You may have a partially installed environment. Try `Pkg.instantiate()`
│      to ensure all packages in the environment are installed.
│    - Or, if you have Optimization checked out for development and have
│      added Zygote as a dependency but haven't updated your primary
│      environment's manifest file, try `Pkg.resolve()`.
│    - Otherwise you may need to report an issue with Optimization
│    Stacktrace:
│      [1] macro expansion
│        @ ./loading.jl:1167 [inlined]
│      [2] macro expansion
│        @ ./lock.jl:223 [inlined]
│      [3] require(into::Module, mod::Symbol)
│        @ Base ./loading.jl:1144
│      [4] include(mod::Module, _path::String)
│        @ Base ./Base.jl:419
│      [5] include(x::String)
│        @ Optimization ~/.julia/packages/Optimization/q952d/src/Optimization.jl:4
│      [6] macro expansion
│        @ ~/.julia/packages/Requires/Z8rfN/src/Requires.jl:40 [inlined]
│      [7] top-level scope
│        @ ~/.julia/packages/Optimization/q952d/src/Optimization.jl:46
│      [8] eval
│        @ ./boot.jl:368 [inlined]
│      [9] eval
│        @ ~/.julia/packages/Optimization/q952d/src/Optimization.jl:4 [inlined]
│     [10] (::Optimization.var"#48#69")()
│        @ Optimization ~/.julia/packages/Requires/Z8rfN/src/require.jl:101
│     [11] macro expansion
│        @ timing.jl:382 [inlined]
│     [12] err(f::Any, listener::Module, modname::String, file::String, line::Any)
│        @ Requires ~/.julia/packages/Requires/Z8rfN/src/require.jl:47
│     [13] (::Optimization.var"#47#68")()
│        @ Optimization ~/.julia/packages/Requires/Z8rfN/src/require.jl:100
│     [14] withpath(f::Any, path::String)
│        @ Requires ~/.julia/packages/Requires/Z8rfN/src/require.jl:37
│     [15] (::Optimization.var"#46#67")()
│        @ Optimization ~/.julia/packages/Requires/Z8rfN/src/require.jl:99
│     [16] listenpkg(f::Any, pkg::Base.PkgId)
│        @ Requires ~/.julia/packages/Requires/Z8rfN/src/require.jl:20
│     [17] macro expansion
│        @ ~/.julia/packages/Requires/Z8rfN/src/require.jl:98 [inlined]
│     [18] __init__()
│        @ Optimization ~/.julia/packages/Optimization/q952d/src/Optimization.jl:45
│     [19] _include_from_serialized(pkg::Base.PkgId, path::String, depmods::Vector{Any})
│        @ Base ./loading.jl:831
│     [20] _tryrequire_from_serialized(modkey::Base.PkgId, path::String, sourcepath::String, depmods::Vector{Any})
│        @ Base ./loading.jl:938
│     [21] _require_search_from_serialized(pkg::Base.PkgId, sourcepath::String, build_id::UInt64)
│        @ Base ./loading.jl:1028
│     [22] _require(pkg::Base.PkgId)
│        @ Base ./loading.jl:1315
│     [23] _require_prelocked(uuidkey::Base.PkgId)
│        @ Base ./loading.jl:1200
│     [24] macro expansion
│        @ ./loading.jl:1180 [inlined]
│     [25] macro expansion
│        @ ./lock.jl:223 [inlined]
│     [26] require(into::Module, mod::Symbol)
│        @ Base ./loading.jl:1144
│     [27] eval
│        @ ./boot.jl:368 [inlined]
│     [28] include_string(mapexpr::typeof(REPL.softscope), mod::Module, code::String, filename::String)
│        @ Base ./loading.jl:1428
│     [29] invokelatest(::Any, ::Any, ::Vararg{Any}; kwargs::Base.Pairs{Symbol, Union{}, Tuple{}, NamedTuple{(), Tuple{}}})
│        @ Base ./essentials.jl:729
│     [30] invokelatest(::Any, ::Any, ::Vararg{Any})
│        @ Base ./essentials.jl:726
│     [31] inlineeval(m::Module, code::String, code_line::Int64, code_column::Int64, file::String; softscope::Bool)
│        @ VSCodeServer ~/.vscode-server/extensions/julialang.language-julia-1.47.2/scripts/packages/VSCodeServer/src/eval.jl:233
│     [32] (::VSCodeServer.var"#66#70"{Bool, Bool, Bool, Module, String, Int64, Int64, String, VSCodeServer.ReplRunCodeRequestParams})()
│        @ VSCodeServer ~/.vscode-server/extensions/julialang.language-julia-1.47.2/scripts/packages/VSCodeServer/src/eval.jl:157
│     [33] withpath(f::VSCodeServer.var"#66#70"{Bool, Bool, Bool, Module, String, Int64, Int64, String, VSCodeServer.ReplRunCodeRequestParams}, path::String)
│        @ VSCodeServer ~/.vscode-server/extensions/julialang.language-julia-1.47.2/scripts/packages/VSCodeServer/src/repl.jl:249
│     [34] (::VSCodeServer.var"#65#69"{Bool, Bool, Bool, Module, String, Int64, Int64, String, VSCodeServer.ReplRunCodeRequestParams})()
│        @ VSCodeServer ~/.vscode-server/extensions/julialang.language-julia-1.47.2/scripts/packages/VSCodeServer/src/eval.jl:155
│     [35] hideprompt(f::VSCodeServer.var"#65#69"{Bool, Bool, Bool, Module, String, Int64, Int64, String, VSCodeServer.ReplRunCodeRequestParams})
│        @ VSCodeServer ~/.vscode-server/extensions/julialang.language-julia-1.47.2/scripts/packages/VSCodeServer/src/repl.jl:38
│     [36] (::VSCodeServer.var"#64#68"{Bool, Bool, Bool, Module, String, Int64, Int64, String, VSCodeServer.ReplRunCodeRequestParams})()
│        @ VSCodeServer ~/.vscode-server/extensions/julialang.language-julia-1.47.2/scripts/packages/VSCodeServer/src/eval.jl:126
│     [37] with_logstate(f::Function, logstate::Any)
│        @ Base.CoreLogging ./logging.jl:511
│     [38] with_logger
│        @ ./logging.jl:623 [inlined]
│     [39] (::VSCodeServer.var"#63#67"{VSCodeServer.ReplRunCodeRequestParams})()
│        @ VSCodeServer ~/.vscode-server/extensions/julialang.language-julia-1.47.2/scripts/packages/VSCodeServer/src/eval.jl:225
│     [40] #invokelatest#2
│        @ ./essentials.jl:729 [inlined]
│     [41] invokelatest(::Any)
│        @ Base ./essentials.jl:726
│     [42] macro expansion
│        @ ~/.vscode-server/extensions/julialang.language-julia-1.47.2/scripts/packages/VSCodeServer/src/eval.jl:34 [inlined]
│     [43] (::VSCodeServer.var"#61#62")()
│        @ VSCodeServer ./task.jl:484
│    in expression starting at /home/ga48kuh/.julia/packages/Optimization/q952d/ext/OptimizationZygoteExt.jl:1
└ @ Requires ~/.julia/packages/Requires/Z8rfN/src/require.jl:51

I suppose this is related, but don't know how to fix it. Any ideas?

[E-B-Manohar]

I faced same issue, using julia 1.9.1 resolved it.

[ChrisRackauckas]

@Vaibhavdixit02

[Vaibhavdixit02]

@E-B-Manohar Can you post the package versions ]st you are using?

[Vaibhavdixit02]

@flmuk from your Manifest I can see you are on Optimization 3.14, please update to 3.15 that should fix it for you

[E-B-Manohar]

@E-B-Manohar Can you post the package versions ]st you are using?

[7073ff75] IJulia v1.24.2
[b2108857] Lux v0.4.54
[961ee093] ModelingToolkit v8.59.1
[315f7962] NeuralPDE v5.7.0
[7f7a1694] Optimization v3.15.2
[36348300] OptimizationOptimJL v0.1.9
[42dfb2eb] OptimizationOptimisers v0.1.4
[91a5bcdd] Plots v1.38.16
[e88e6eb3] Zygote v0.6.62

[Vaibhavdixit02]

This is on the 1.9 julia that worked for you or the 1.8 environment that didn't work?

[E-B-Manohar]

This is on the 1.9 julia that worked for you or the 1.8 environment that didn't work?

Earlier I was using Julia 1.6.9. Then I faced this error.
After reinstalling Julia with version 1.9.1, this error vanished

[Vaibhavdixit02]

I think on 1.6 you might have had older package versions and hence got the error. It should work if you update packages

[E-B-Manohar]

I think on 1.6 you might have had older package versions and hence got the error. It should work if you update packages

Yeah, Probably you are right.

[flmuk]

Thank you @Vaibhavdixit02 , this helped!