Resolve gradient mismatches in benchmarks

[seabbs]

For several utilities, benchmarking suggests that different backends given different gradients. This should be investigated as it may indicate performance issues.

[SamuelBrand1]

Is the difference between all options or is Zygote the outlier? Reverse diff with compiled tape is known to have these problems with logical branches in the code.

[seabbs]

Compiled tape has issues.

[SamuelBrand1]

That makes sense... The improvement path here is track down the "wrong" branch(es) that are getting compiled.

[seabbs]

This is what I see in our current benchmarks. Could really do with a improved warning message here to help localise

[seabbs]

In the latest benchmarks in #392 I still see a single instance of this that needs resolving.

[SamuelBrand1]

Where is this benchmark?

[seabbs]

I think we can also use instabilities in our benchmarks (i.e #400 (comment)) to indicate where problems are. It would be useful to think if there is a more formal way of checking this that requires less tracking across PRs.

(i.e here it suggests that observation error models are problematic).

[seabbs]

#414 localised some issues to the NegativeBinomialError model. It would be good to investigate this further to see if it common across all error models or just the negative binomial.

See: #414 (comment)

[seabbs]

Running some more repititions I see the following throwing gradient issues (due to compiled reverse diff):

Type	Count
Ascertainment{NegativeBinomialError}	3
NegativeBinomialError{HalfNormal{Float64}}	2

Warnings from Model{typeof(generate_observations), (:obs_model, :y_t, :Y_t), (), (), Tuple{Ascertainment{NegativeBinomialError{HalfNormal{Float64}}, AbstractTuringLatentModel, var"#88#89", String}, Vector{Int64}, Vector{Int64}}, Tuple{}, DefaultContext}(EpiAware.EpiAwareBase.generate_observations, (obs_model = Ascertainment{NegativeBinomialError{HalfNormal{Float64}}, AbstractTuringLatentModel, var"#88#89", String}(NegativeBinomialError{HalfNormal{Float64}}(HalfNormal{Float64}(μ=0.01)), PrefixLatentModel{FixedIntercept{Float64}, String}(FixedIntercept{Float64}(0.1), "Ascertainment"), var"#88#89"(), "Ascertainment"), y_t = [100, 100, 100, 100, 100, 100, 100, 100, 100, 100], Y_t = [100, 100, 100, 100, 100, 100, 100, 100, 100, 100]), NamedTuple(), DefaultContext()):
┌ Warning: `ad.compile` where `ad` is `AutoReverseDiff` has been deprecated and will be removed in v2. Instead it is available as a compile-time constant as `AutoReverseDiff{true}` or `AutoReverseDiff{false}

Warnings from Model{typeof(generate_observations), (:obs_model, :y_t, :Y_t), (), (), Tuple{Ascertainment{NegativeBinomialError{HalfNormal{Float64}}, AbstractTuringLatentModel, var"#82#83", String}, Vector{Int64}, Vector{Int64}}, Tuple{}, DefaultContext}(EpiAware.EpiAwareBase.generate_observations, (obs_model = Ascertainment{NegativeBinomialError{HalfNormal{Float64}}, AbstractTuringLatentModel, var"#82#83", String}(NegativeBinomialError{HalfNormal{Float64}}(HalfNormal{Float64}(μ=0.01)), PrefixLatentModel{FixedIntercept{Float64}, String}(FixedIntercept{Float64}(0.1), "Ascertainment"), var"#82#83"(), "Ascertainment"), y_t = [100, 100, 100, 100, 100, 100, 100, 100, 100, 100], Y_t = [100, 100, 100, 100, 100, 100, 100, 100, 100, 100]), NamedTuple(), DefaultContext()):

Warnings from Model{typeof(generate_observations), (:obs_model, :y_t, :Y_t), (), (), Tuple{Ascertainment{NegativeBinomialError{HalfNormal{Float64}}, AbstractTuringLatentModel, var"#64#65", String}, Vector{Int64}, Vector{Int64}}, Tuple{}, DefaultContext}(EpiAware.EpiAwareBase.generate_observations, (obs_model = Ascertainment{NegativeBinomialError{HalfNormal{Float64}}, AbstractTuringLatentModel, var"#64#65", String}(NegativeBinomialError{HalfNormal{Float64}}(HalfNormal{Float64}(μ=0.01)), PrefixLatentModel{FixedIntercept{Float64}, String}(FixedIntercept{Float64}(0.1), "Ascertainment"), var"#64#65"(), "Ascertainment"), y_t = [100, 100, 100, 100, 100, 100, 100, 100, 100, 100], Y_t = [100, 100, 100, 100, 100, 100, 100, 100, 100, 100]), NamedTuple(), DefaultContext())

Warnings from Model{typeof(generate_observations), (:obs_model, :y_t, :Y_t), (), (), Tuple{NegativeBinomialError{HalfNormal{Float64}}, Vector{Float64}, Vector{Float64}}, Tuple{}, DefaultContext}(EpiAware.EpiAwareBase.generate_observations, (obs_model = NegativeBinomialError{HalfNormal{Float64}}(HalfNormal{Float64}(μ=0.01)), y_t = [10.0, 10.0, 10.0, 10.0, 10.0, 10.0, 10.0, 10.0, 10.0, 10.0], Y_t = [10.0, 10.0, 10.0, 10.0, 10.0, 10.0, 10.0, 10.0, 10.0, 10.0]), NamedTuple(), DefaultContext())

arnings from Model{typeof(generate_observations), (:obs_model, :y_t, :Y_t), (), (), Tuple{NegativeBinomialError{HalfNormal{Float64}}, Vector{Float64}, Vector{Float64}}, Tuple{}, DefaultContext}(EpiAware.EpiAwareBase.generate_observations, (obs_model = NegativeBinomialError{HalfNormal{Float64}}(HalfNormal{Float64}(μ=0.01)), y_t = [10.0, 10.0, 10.0, 10.0, 10.0, 10.0, 10.0, 10.0, 10.0, 10.0], Y_t = [10.0, 10.0, 10.0, 10.0, 10.0, 10.0, 10.0, 10.0, 10.0, 10.0]), NamedTuple(), DefaultContext())

Something of a pattern I think!

[seabbs]

I think with #442 and #415 these are now all handled so closing.