MethodError: no method matching getindex(::Cassette.Tagged{...}, ::UnitRange{Int64})

[ferrolho]

I was revisiting a minimal working example from an old issue (#7 (comment)) and I have run into a MethodError. The code snippet and the full stacktrace of the error are shown below.

Detail: the original function takes three vectors as inputs: q, q̇, and q̈, but in order to use it with sparsity! I first concatenate them all into x and then retrieve them from within the function. I believe this is the right thing to do, but correct me if there's a better way.

using SparsityDetection

function EulerStep(dx, x)
    Δt = 0.001
    qᵢ = x[ 1: 7]
    q̇ᵢ = x[ 8:14]
    q̈ᵢ = x[15:21]

    dx[ 1: 7] = qᵢ + Δt * q̇ᵢ
    dx[ 8:14] = q̇ᵢ + Δt * q̈ᵢ

    nothing
end

input = rand(3*7)
output = zeros(2*7)
sparsity_pattern = sparsity!(EulerStep, output, input)

ERROR: MethodError: no method matching getindex(::Cassette.Tagged{Cassette.Tag{nametype(JacobianSparsityContext),0xabc61d194ec28df5,Nothing},Array{Float64,1},Union{SparsityDetection.JacInput, SparsityDetection.JacOutput, SparsityDetection.ProvinanceSet},Array{Cassette.Meta{SparsityDetection.ProvinanceSet,Cassette.NoMetaMeta},1},Cassette.Context{nametype(JacobianSparsityContext),Sparsity,Cassette.Tag{nametype(JacobianSparsityContext),0xabc61d194ec28df5,Nothing},Cassette.var"##PassType#255",IdDict{Module,Dict{Symbol,Cassette.BindingMeta}},Cassette.DisableHooks}}, ::UnitRange{Int64})
Stacktrace:
 [1] EulerStep(::Cassette.Tagged{Cassette.Tag{nametype(JacobianSparsityContext),0xabc61d194ec28df5,Nothing},Array{Float64,1},Union{SparsityDetection.JacInput, SparsityDetection.JacOutput, SparsityDetection.ProvinanceSet},Array{Cassette.Meta{SparsityDetection.ProvinanceSet,Cassette.NoMetaMeta},1},Cassette.Context{nametype(JacobianSparsityContext),Sparsity,Cassette.Tag{nametype(JacobianSparsityContext),0xabc61d194ec28df5,Nothing},Cassette.var"##PassType#255",IdDict{Module,Dict{Symbol,Cassette.BindingMeta}},Cassette.DisableHooks}}, ::Cassette.Tagged{Cassette.Tag{nametype(JacobianSparsityContext),0xabc61d194ec28df5,Nothing},Array{Float64,1},Union{SparsityDetection.JacInput, SparsityDetection.JacOutput, SparsityDetection.ProvinanceSet},Array{Cassette.Meta{SparsityDetection.ProvinanceSet,Cassette.NoMetaMeta},1},Cassette.Context{nametype(JacobianSparsityContext),Sparsity,Cassette.Tag{nametype(JacobianSparsityContext),0xabc61d194ec28df5,Nothing},Cassette.var"##PassType#255",IdDict{Module,Dict{Symbol,Cassette.BindingMeta}},Cassette.DisableHooks}}) at ./REPL[4]:3
 [2] call at /home/henrique/.julia/packages/Cassette/YCOeN/src/context.jl:448 [inlined]
 [3] fallback at /home/henrique/.julia/packages/Cassette/YCOeN/src/context.jl:445 [inlined]
 [4] recurse(::Cassette.Context{nametype(JacobianSparsityContext),Tuple{Sparsity,SparsityDetection.Path},Cassette.Tag{nametype(JacobianSparsityContext),0xabc61d194ec28df5,Nothing},SparsityDetection.var"##PassType#253",IdDict{Module,Dict{Symbol,Cassette.BindingMeta}},Cassette.DisableHooks}, ::typeof(Core._apply_iterate), ::typeof(iterate), ::typeof(EulerStep), ::Tuple{Cassette.Tagged{Cassette.Tag{nametype(JacobianSparsityContext),0xabc61d194ec28df5,Nothing},Array{Float64,1},Union{SparsityDetection.JacInput, SparsityDetection.JacOutput, SparsityDetection.ProvinanceSet},Array{Cassette.Meta{SparsityDetection.ProvinanceSet,Cassette.NoMetaMeta},1},Cassette.Context{nametype(JacobianSparsityContext),Sparsity,Cassette.Tag{nametype(JacobianSparsityContext),0xabc61d194ec28df5,Nothing},Cassette.var"##PassType#255",IdDict{Module,Dict{Symbol,Cassette.BindingMeta}},Cassette.DisableHooks}},Cassette.Tagged{Cassette.Tag{nametype(JacobianSparsityContext),0xabc61d194ec28df5,Nothing},Array{Float64,1},Union{SparsityDetection.JacInput, SparsityDetection.JacOutput, SparsityDetection.ProvinanceSet},Array{Cassette.Meta{SparsityDetection.ProvinanceSet,Cassette.NoMetaMeta},1},Cassette.Context{nametype(JacobianSparsityContext),Sparsity,Cassette.Tag{nametype(JacobianSparsityContext),0xabc61d194ec28df5,Nothing},Cassette.var"##PassType#255",IdDict{Module,Dict{Symbol,Cassette.BindingMeta}},Cassette.DisableHooks}}}) at /home/henrique/.julia/packages/Cassette/YCOeN/src/overdub.jl:481
 [5] overdub(::Cassette.Context{nametype(JacobianSparsityContext),Tuple{Sparsity,SparsityDetection.Path},Cassette.Tag{nametype(JacobianSparsityContext),0xabc61d194ec28df5,Nothing},SparsityDetection.var"##PassType#253",IdDict{Module,Dict{Symbol,Cassette.BindingMeta}},Cassette.DisableHooks}, ::Function, ::Function, ::Function, ::Tuple{Cassette.Tagged{Cassette.Tag{nametype(JacobianSparsityContext),0xabc61d194ec28df5,Nothing},Array{Float64,1},Union{SparsityDetection.JacInput, SparsityDetection.JacOutput, SparsityDetection.ProvinanceSet},Array{Cassette.Meta{SparsityDetection.ProvinanceSet,Cassette.NoMetaMeta},1},Cassette.Context{nametype(JacobianSparsityContext),Sparsity,Cassette.Tag{nametype(JacobianSparsityContext),0xabc61d194ec28df5,Nothing},Cassette.var"##PassType#255",IdDict{Module,Dict{Symbol,Cassette.BindingMeta}},Cassette.DisableHooks}},Cassette.Tagged{Cassette.Tag{nametype(JacobianSparsityContext),0xabc61d194ec28df5,Nothing},Array{Float64,1},Union{SparsityDetection.JacInput, SparsityDetection.JacOutput, SparsityDetection.ProvinanceSet},Array{Cassette.Meta{SparsityDetection.ProvinanceSet,Cassette.NoMetaMeta},1},Cassette.Context{nametype(JacobianSparsityContext),Sparsity,Cassette.Tag{nametype(JacobianSparsityContext),0xabc61d194ec28df5,Nothing},Cassette.var"##PassType#255",IdDict{Module,Dict{Symbol,Cassette.BindingMeta}},Cassette.DisableHooks}}}) at /home/henrique/.julia/packages/SparsityDetection/PbKzm/src/propagate_tags.jl:58
 [6] #2 at /home/henrique/.julia/packages/SparsityDetection/PbKzm/src/controlflow.jl:148 [inlined]
 [7] recurse(::Cassette.Context{nametype(JacobianSparsityContext),Tuple{Sparsity,SparsityDetection.Path},Cassette.Tag{nametype(JacobianSparsityContext),0xabc61d194ec28df5,Nothing},SparsityDetection.var"##PassType#253",IdDict{Module,Dict{Symbol,Cassette.BindingMeta}},Cassette.DisableHooks}, ::SparsityDetection.var"#2#3"{typeof(EulerStep),Tuple{Cassette.Tagged{Cassette.Tag{nametype(JacobianSparsityContext),0xabc61d194ec28df5,Nothing},Array{Float64,1},Union{SparsityDetection.JacInput, SparsityDetection.JacOutput, SparsityDetection.ProvinanceSet},Array{Cassette.Meta{SparsityDetection.ProvinanceSet,Cassette.NoMetaMeta},1},Cassette.Context{nametype(JacobianSparsityContext),Sparsity,Cassette.Tag{nametype(JacobianSparsityContext),0xabc61d194ec28df5,Nothing},Cassette.var"##PassType#255",IdDict{Module,Dict{Symbol,Cassette.BindingMeta}},Cassette.DisableHooks}},Cassette.Tagged{Cassette.Tag{nametype(JacobianSparsityContext),0xabc61d194ec28df5,Nothing},Array{Float64,1},Union{SparsityDetection.JacInput, SparsityDetection.JacOutput, SparsityDetection.ProvinanceSet},Array{Cassette.Meta{SparsityDetection.ProvinanceSet,Cassette.NoMetaMeta},1},Cassette.Context{nametype(JacobianSparsityContext),Sparsity,Cassette.Tag{nametype(JacobianSparsityContext),0xabc61d194ec28df5,Nothing},Cassette.var"##PassType#255",IdDict{Module,Dict{Symbol,Cassette.BindingMeta}},Cassette.DisableHooks}}}}) at /home/henrique/.julia/packages/Cassette/YCOeN/src/overdub.jl:0
 [8] abstract_run(::SparsityDetection.var"#22#24", ::Cassette.Context{nametype(JacobianSparsityContext),Sparsity,Cassette.Tag{nametype(JacobianSparsityContext),0xabc61d194ec28df5,Nothing},Cassette.var"##PassType#255",IdDict{Module,Dict{Symbol,Cassette.BindingMeta}},Cassette.DisableHooks}, ::Function, ::Cassette.Tagged{Cassette.Tag{nametype(JacobianSparsityContext),0xabc61d194ec28df5,Nothing},Array{Float64,1},Union{SparsityDetection.JacInput, SparsityDetection.JacOutput, SparsityDetection.ProvinanceSet},Array{Cassette.Meta{SparsityDetection.ProvinanceSet,Cassette.NoMetaMeta},1},Cassette.Context{nametype(JacobianSparsityContext),Sparsity,Cassette.Tag{nametype(JacobianSparsityContext),0xabc61d194ec28df5,Nothing},Cassette.var"##PassType#255",IdDict{Module,Dict{Symbol,Cassette.BindingMeta}},Cassette.DisableHooks}}, ::Vararg{Cassette.Tagged{Cassette.Tag{nametype(JacobianSparsityContext),0xabc61d194ec28df5,Nothing},Array{Float64,1},Union{SparsityDetection.JacInput, SparsityDetection.JacOutput, SparsityDetection.ProvinanceSet},Array{Cassette.Meta{SparsityDetection.ProvinanceSet,Cassette.NoMetaMeta},1},Cassette.Context{nametype(JacobianSparsityContext),Sparsity,Cassette.Tag{nametype(JacobianSparsityContext),0xabc61d194ec28df5,Nothing},Cassette.var"##PassType#255",IdDict{Module,Dict{Symbol,Cassette.BindingMeta}},Cassette.DisableHooks}},N} where N; verbose::Bool) at /home/henrique/.julia/packages/SparsityDetection/PbKzm/src/controlflow.jl:148
 [9] jacobian_sparsity(::Function, ::Array{Float64,1}, ::Array{Float64,1}; sparsity::Sparsity, verbose::Bool, raw::Bool) at /home/henrique/.julia/packages/SparsityDetection/PbKzm/src/jacobian.jl:135
 [10] jacobian_sparsity(::Function, ::Array{Float64,1}, ::Array{Float64,1}) at /home/henrique/.julia/packages/SparsityDetection/PbKzm/src/jacobian.jl:130
 [11] sparsity!(::Function, ::Vararg{Any,N} where N; kwargs::Base.Iterators.Pairs{Union{},Union{},Tuple{},NamedTuple{(),Tuple{}}}) at /home/henrique/.julia/packages/SparsityDetection/PbKzm/src/SparsityDetection.jl:19
 [12] sparsity!(::Function, ::Vararg{Any,N} where N) at /home/henrique/.julia/packages/SparsityDetection/PbKzm/src/SparsityDetection.jl:19
 [13] top-level scope at REPL[7]:1

[ferrolho]

I am closing this issue. The code snippet above is no longer throwing an error. I could swear I tried this on a fresh environment yesterday... Oh well, my apologies.

[ChrisRackauckas]

Awesome!