Integrate DifferentiationInterface.jl for gradient computation

.gitignore

@@ -29,4 +29,6 @@ Manifest.toml
 *.local.*
 
 # gitingest generated files
-digest.txt
+digest.txt
+
+tmp/

JuliaBUGS/History.md

@@ -1,5 +1,15 @@
 # JuliaBUGS Changelog
 
+## 0.10.4
+
+- **DifferentiationInterface.jl integration**: JuliaBUGS now uses [DifferentiationInterface.jl](https://github.com/JuliaDiff/DifferentiationInterface.jl) for automatic differentiation, providing a unified interface to multiple AD backends.
+  - Add `adtype` parameter to `compile()` function for specifying AD backends
+  - Support convenient symbol shortcuts: `:ReverseDiff`, `:ForwardDiff`, `:Zygote`, `:Enzyme`
+  - Gradient computation is prepared during compilation for optimal performance
+  - Example: `model = compile(model_def, data; adtype=:ReverseDiff)`
+  - Full control available via explicit ADTypes: `adtype=AutoReverseDiff(compile=true)`
+  - Backward compatible: models without `adtype` work as before
+
 ## 0.10.1
 
 Expose docs for changes in [v0.10.0](https://github.com/TuringLang/JuliaBUGS.jl/releases/tag/JuliaBUGS-v0.10.0)

JuliaBUGS/Project.toml

@@ -1,6 +1,6 @@
 name = "JuliaBUGS"
 uuid = "ba9fb4c0-828e-4473-b6a1-cd2560fee5bf"
-version = "0.10.3"
+version = "0.10.4"
 
 [deps]
 ADTypes = "47edcb42-4c32-4615-8424-f2b9edc5f35b"
@@ -9,6 +9,7 @@ AbstractPPL = "7a57a42e-76ec-4ea3-a279-07e840d6d9cf"
 Accessors = "7d9f7c33-5ae7-4f3b-8dc6-eff91059b697"
 BangBang = "198e06fe-97b7-11e9-32a5-e1d131e6ad66"
 Bijectors = "76274a88-744f-5084-9051-94815aaf08c4"
+DifferentiationInterface = "a0c0ee7d-e4b9-4e03-894e-1c5f64a51d63"
 Distributions = "31c24e10-a181-5473-b8eb-7969acd0382f"
 Documenter = "e30172f5-a6a5-5a46-863b-614d45cd2de4"
 Graphs = "86223c79-3864-5bf0-83f7-82e725a168b6"
@@ -52,6 +53,7 @@ AdvancedHMC = "0.6, 0.7, 0.8"
 AdvancedMH = "0.8"
 BangBang = "0.4.1"
 Bijectors = "0.13, 0.14, 0.15.5"
+DifferentiationInterface = "0.7"
 Distributions = "0.23.8, 0.24, 0.25"
 Documenter = "0.27, 1"
 GLMakie = "0.10, 0.11, 0.12, 0.13"

JuliaBUGS/benchmark/benchmark.jl

@@ -83,16 +83,15 @@ function _create_results_dataframe(results::OrderedDict{Symbol,BenchmarkResult})
             ),
         )
     end
+    DataFrames.rename!(
+        df,
+        :Density_Time => "Density Time (µs)",
+        :Density_Gradient_Time => "Density+Gradient Time (µs)",
+    )
     return df
 end
 
-function _print_results_table(
-    results::OrderedDict{Symbol,BenchmarkResult}; backend=Val(:text)
-)
+function _print_results_table(results::OrderedDict{Symbol,BenchmarkResult}; backend=:text)
     df = _create_results_dataframe(results)
-    return pretty_table(
-        df;
-        header=["Model", "Parameters", "Density Time (µs)", "Density+Gradient Time (µs)"],
-        backend=backend,
-    )
+    return pretty_table(df; backend=backend)
 end

JuliaBUGS/benchmark/run_benchmarks.jl

@@ -45,7 +45,7 @@ for (model_name, model) in zip(examples_to_benchmark, juliabugs_models)
 end
 
 println("### Stan results:")
-_print_results_table(stan_results; backend=Val(:markdown))
+_print_results_table(stan_results; backend=:markdown)
 
 println("### JuliaBUGS Mooncake results:")
-_print_results_table(juliabugs_results; backend=Val(:markdown))
+_print_results_table(juliabugs_results; backend=:markdown)

JuliaBUGS/docs/src/example.md

@@ -190,40 +190,62 @@ initialize!(model, initializations)
 initialize!(model, rand(26))
 ```
 
-`LogDensityProblemsAD.jl` defined some extensions that support automatic differentiation packages.
-For example, with `ReverseDiff.jl`
+### Automatic Differentiation
+
+JuliaBUGS integrates with automatic differentiation (AD) through [DifferentiationInterface.jl](https://github.com/JuliaDiff/DifferentiationInterface.jl), enabling gradient-based inference methods like Hamiltonian Monte Carlo (HMC) and No-U-Turn Sampler (NUTS).
+
+#### Specifying an AD Backend
+
+To compile a model with gradient support, pass the `adtype` parameter to `compile`:
 
 ```julia
-using LogDensityProblemsAD, ReverseDiff
+# Using explicit ADType from ADTypes.jl
+using ADTypes
+model = compile(model_def, data; adtype=AutoReverseDiff(compile=true))
+
+# Using convenient symbol shortcuts
+model = compile(model_def, data; adtype=:ReverseDiff)  # Equivalent to above
+```
 
-ad_model = ADgradient(:ReverseDiff, model; compile=Val(true))
+Available AD backends include:
+- `:ReverseDiff` - ReverseDiff with tape compilation (recommended for most models)
+- `:ForwardDiff` - ForwardDiff (efficient for models with few parameters)
+- `:Zygote` - Zygote (source-to-source AD)
+- `:Enzyme` - Enzyme (experimental, high-performance)
+
+For fine-grained control, use explicit `ADTypes` constructors:
+
+```julia
+# ReverseDiff without compilation
+model = compile(model_def, data; adtype=AutoReverseDiff(compile=false))
 ```
 
-Here `ad_model` will also implement all the interfaces of [`LogDensityProblems.jl`](https://www.tamaspapp.eu/LogDensityProblems.jl/dev/).
-`LogDensityProblemsAD.jl` will automatically add the interface function [`logdensity_and_gradient`](https://www.tamaspapp.eu/LogDensityProblems.jl/dev/#LogDensityProblems.logdensity_and_gradient) to the model, which will return the log density and gradient of the model.  
-And `ad_model` can be used in the same way as `model` in the example below.
+The compiled model with gradient support implements the [`LogDensityProblems.jl`](https://www.tamaspapp.eu/LogDensityProblems.jl/dev/) interface, including [`logdensity_and_gradient`](https://www.tamaspapp.eu/LogDensityProblems.jl/dev/#LogDensityProblems.logdensity_and_gradient), which returns both the log density and its gradient.
 
 ### Inference
 
-For a differentiable model, we can use [`AdvancedHMC.jl`](https://github.com/TuringLang/AdvancedHMC.jl) to perform inference.
-For instance,
+For gradient-based inference, we use [`AdvancedHMC.jl`](https://github.com/TuringLang/AdvancedHMC.jl) with models compiled with an `adtype`:
 
 ```julia
-using AdvancedHMC, AbstractMCMC, LogDensityProblems, MCMCChains
+using AdvancedHMC, AbstractMCMC, LogDensityProblems, MCMCChains, ReverseDiff
+
+# Compile with gradient support
+model = compile(model_def, data; adtype=:ReverseDiff)
 
 n_samples, n_adapts = 2000, 1000
 
 D = LogDensityProblems.dimension(model); initial_θ = rand(D)
 
 samples_and_stats = AbstractMCMC.sample(
-                        ad_model,
+                        model,
                         NUTS(0.8),
                         n_samples;
                         chain_type = Chains,
                         n_adapts = n_adapts,
                         init_params = initial_θ,
                         discard_initial = n_adapts
                     )
+describe(samples_and_stats)
 ```
 
 This will return the MCMC Chain,
@@ -234,39 +256,72 @@ Chains MCMC chain (2000×40×1 Array{Real, 3}):
 Iterations        = 1001:1:3000
 Number of chains  = 1
 Samples per chain = 2000
-parameters        = alpha0, alpha12, alpha1, alpha2, tau, b[16], b[12], b[10], b[14], b[13], b[7], b[6], b[20], b[1], b[4], b[5], b[2], b[18], b[8], b[3], b[9], b[21], b[17], b[15], b[11], b[19], sigma
+parameters        = tau, alpha12, alpha2, alpha1, alpha0, b[1], b[2], b[3], b[4], b[5], b[6], b[7], b[8], b[9], b[10], b[11], b[12], b[13], b[14], b[15], b[16], b[17], b[18], b[19], b[20], b[21], sigma
 internals         = lp, n_steps, is_accept, acceptance_rate, log_density, hamiltonian_energy, hamiltonian_energy_error, max_hamiltonian_energy_error, tree_depth, numerical_error, step_size, nom_step_size, is_adapt
 
 Summary Statistics
-  parameters      mean       std      mcse    ess_bulk    ess_tail      rhat   ess_per_sec
-      Symbol   Float64   Float64   Float64        Real     Float64   Float64       Missing
-
-      alpha0   -0.5642    0.2320    0.0084    766.9305   1022.5211    1.0021       missing
-     alpha12   -0.8489    0.5247    0.0170    946.0418   1044.1109    1.0002       missing
-      alpha1    0.0587    0.3715    0.0119    966.4367   1233.2257    1.0007       missing
-      alpha2    1.3852    0.3410    0.0127    712.2978    974.1566    1.0002       missing
-         tau    1.8880    0.7705    0.0447    348.9331    338.3655    1.0030       missing
-       b[16]   -0.2445    0.4459    0.0132   1528.0578    843.8225    1.0003       missing
-       b[12]    0.2050    0.3602    0.0086   1868.6126   1202.1363    0.9996       missing
-       b[10]   -0.3500    0.2893    0.0090   1047.3119   1245.9358    1.0008       missing
-      ⋮           ⋮         ⋮         ⋮          ⋮           ⋮          ⋮           ⋮
-                                                                             19 rows omitted
+  parameters      mean        std      mcse    ess_bulk    ess_tail      rhat   ess_per_sec 
+      Symbol   Float64    Float64   Float64        Real     Float64   Float64       Missing
+
+         tau   73.1490   193.8441   43.2582     56.3430     20.6688    1.0155       missing
+     alpha12   -0.8052     0.4392    0.0158    761.2180   1049.1664    1.0020       missing
+      alpha2    1.3428     0.2813    0.0140    422.8810   1013.2570    1.0061       missing
+      alpha1    0.0845     0.3126    0.0113    773.2202    981.8487    1.0051       missing
+      alpha0   -0.5480     0.1944    0.0087    537.6212   1156.2083    1.0014       missing
+        b[1]   -0.1905     0.2540    0.0129    374.3372    971.7526    1.0034       missing
+        b[2]    0.0161     0.2178    0.0056   1505.6353   1002.8787    1.0001       missing
+        b[3]   -0.1986     0.2375    0.0128    367.6766   1287.8215    1.0015       missing
+        b[4]    0.2792     0.2498    0.0163    201.1558   1168.7538    1.0068       missing
+        b[5]    0.1170     0.2397    0.0092    659.5422   1484.8584    1.0016       missing
+        b[6]    0.0667     0.2821    0.0074   1745.5567    902.1014    1.0067       missing
+        b[7]    0.0597     0.2218    0.0055   1589.5590   1145.6017    1.0065       missing
+        b[8]    0.1769     0.2316    0.0102    554.5974   1318.8089    1.0001       missing
+        b[9]   -0.1257     0.2233    0.0073    930.0346   1186.4283    1.0031       missing
+       b[10]   -0.2513     0.2392    0.0159    213.6323   1142.4487    1.0096       missing
+       b[11]    0.0768     0.2783    0.0081   1376.5999   1218.1537    1.0009       missing
+       b[12]    0.1171     0.2768    0.0079   1354.9409   1130.8217    1.0052       missing
+       b[13]   -0.0688     0.2433    0.0055   1895.0387   1527.7066    1.0010       missing
+       b[14]   -0.1363     0.2558    0.0075   1276.0992   1208.8587    1.0001       missing
+       b[15]    0.2334     0.2757    0.0135    439.2241    837.3396    1.0036       missing
+       b[16]   -0.1212     0.3024    0.0106   1093.4416    914.9457    0.9997       missing
+       b[17]   -0.2120     0.3142    0.0166    360.6420    702.4098    1.0009       missing
+       b[18]    0.0346     0.2282    0.0056   1665.0325   1281.7179    1.0011       missing
+       b[19]   -0.0244     0.2400    0.0052   2186.7638   1179.6971    1.0132       missing
+       b[20]    0.2108     0.2421    0.0131    349.7657   1263.5781    1.0016       missing
+       b[21]   -0.0509     0.2813    0.0061   2200.5614    916.6256    0.9998       missing
+       sigma    0.2797     0.1362    0.0168     56.3430     21.4971    1.0123       missing
 
 Quantiles
-  parameters      2.5%     25.0%     50.0%     75.0%     97.5%
-      Symbol   Float64   Float64   Float64   Float64   Float64
-
-      alpha0   -1.0143   -0.7143   -0.5590   -0.4100   -0.1185
-     alpha12   -1.9063   -1.1812   -0.8296   -0.5153    0.1521
-      alpha1   -0.6550   -0.1822    0.0512    0.2885    0.8180
-      alpha2    0.7214    1.1663    1.3782    1.5998    2.0986
-         tau    0.5461    1.3941    1.8353    2.3115    3.6225
-       b[16]   -1.2359   -0.4836   -0.1909    0.0345    0.5070
-       b[12]   -0.4493   -0.0370    0.1910    0.4375    0.9828
-       b[10]   -0.9570   -0.5264   -0.3331   -0.1514    0.1613
-      ⋮           ⋮         ⋮         ⋮         ⋮         ⋮
-                                                 19 rows omitted
-
+  parameters      2.5%     25.0%     50.0%     75.0%      97.5% 
+      Symbol   Float64   Float64   Float64   Float64    Float64
+
+         tau    3.1280    7.4608   13.0338   28.2289   929.6520
+     alpha12   -1.6645   -1.0887   -0.7952   -0.5635     0.1162
+      alpha2    0.8398    1.1494    1.3233    1.5337     1.9177
+      alpha1   -0.5796   -0.1059    0.1042    0.2883     0.6702
+      alpha0   -0.9340   -0.6751   -0.5463   -0.4086    -0.1752
+        b[1]   -0.7430   -0.3415   -0.1566   -0.0074     0.2535
+        b[2]   -0.4261   -0.1083    0.0192    0.1420     0.4810
+        b[3]   -0.7394   -0.3377   -0.1687   -0.0242     0.2041
+        b[4]   -0.1108    0.0873    0.2409    0.4375     0.8267
+        b[5]   -0.3141   -0.0458    0.0900    0.2563     0.6489
+        b[6]   -0.4679   -0.0896    0.0291    0.2202     0.7060
+        b[7]   -0.3861   -0.0685    0.0534    0.1847     0.5207
+        b[8]   -0.2326    0.0221    0.1505    0.3162     0.6861
+        b[9]   -0.6007   -0.2482   -0.0984    0.0057     0.2771
+       b[10]   -0.7936   -0.4108   -0.2255   -0.0617     0.1290
+       b[11]   -0.4381   -0.0796    0.0353    0.2178     0.7232
+       b[12]   -0.3806   -0.0451    0.0750    0.2671     0.7625
+       b[13]   -0.5841   -0.2135   -0.0443    0.0652     0.4055
+       b[14]   -0.6854   -0.2872   -0.1015    0.0147     0.3476
+       b[15]   -0.2054    0.0257    0.1898    0.4004     0.8660
+       b[16]   -0.8173   -0.2829   -0.0804    0.0532     0.4094
+       b[17]   -0.9071   -0.3911   -0.1595    0.0099     0.2864
+       b[18]   -0.4526   -0.0919    0.0140    0.1686     0.4985
+       b[19]   -0.5055   -0.1547   -0.0091    0.1134     0.4528
+       b[20]   -0.2120    0.0318    0.1788    0.3673     0.7416
+       b[21]   -0.6482   -0.2044   -0.0263    0.1051     0.5246
+       sigma    0.0328    0.1882    0.2770    0.3661     0.5654
 ```
 
 This is consistent with the result in the [OpenBUGS seeds example](https://chjackson.github.io/openbugsdoc/Examples/Seeds.html).
@@ -283,7 +338,7 @@ The model compilation code remains the same, and we can sample multiple chains i
 ```julia
 n_chains = 4
 samples_and_stats = AbstractMCMC.sample(
-    ad_model,
+    model,
     AdvancedHMC.NUTS(0.65),
     AbstractMCMC.MCMCThreads(),
     n_samples,
@@ -311,7 +366,7 @@ For example:
 
 ```julia
 @everywhere begin
-    using JuliaBUGS, LogDensityProblems, LogDensityProblemsAD, AbstractMCMC, AdvancedHMC, MCMCChains, ReverseDiff # also other packages one may need
+    using JuliaBUGS, LogDensityProblems, AbstractMCMC, AdvancedHMC, MCMCChains, ADTypes, ReverseDiff
 
     # Define the functions to use
     # Use `@bugs_primitive` to register the functions to use in the model
@@ -322,7 +377,7 @@ end
 
 n_chains = nprocs() - 1 # use all the processes except the parent process
 samples_and_stats = AbstractMCMC.sample(
-    ad_model,
+    model,
     AdvancedHMC.NUTS(0.65),
     AbstractMCMC.MCMCDistributed(),
     n_samples,
@@ -342,6 +397,67 @@ In this case, we pass two additional arguments to `AbstractMCMC.sample`:
   Note that the `init_params` argument is now a vector of initial parameters for each chain.
   Sometimes the progress logger can cause problems in distributed setting, so we can disable it by setting `progress = false`.
 
+## Choosing an Automatic Differentiation Backend
+
+JuliaBUGS integrates with multiple automatic differentiation (AD) backends through [DifferentiationInterface.jl](https://github.com/JuliaDiff/DifferentiationInterface.jl), providing flexibility to choose the most suitable backend for your model.
+
+### Available Backends
+
+The following AD backends are supported via convenient symbol shortcuts:
+
+- **`:ReverseDiff`** (recommended) — Tape-based reverse-mode AD, highly efficient for models with many parameters. Uses compilation by default for optimal performance.
+- **`:ForwardDiff`** — Forward-mode AD, efficient for models with few parameters (typically < 20).
+- **`:Zygote`** — Source-to-source reverse-mode AD, general-purpose but may be slower than ReverseDiff for many models.
+- **`:Enzyme`** — Experimental high-performance AD backend with LLVM-level transformations.
+
+### Usage Examples
+
+#### Basic Usage with Symbol Shortcuts
+
+The simplest way to specify an AD backend is using symbol shortcuts:
+
+```julia
+# ReverseDiff with tape compilation (recommended for most models)
+model = compile(model_def, data; adtype=:ReverseDiff)
+
+# ForwardDiff (good for small models with few parameters)
+model = compile(model_def, data; adtype=:ForwardDiff)
+
+# Zygote (source-to-source AD)
+model = compile(model_def, data; adtype=:Zygote)
+```
+
+#### Advanced Configuration
+
+For fine-grained control, use explicit `ADTypes` constructors:
+
+```julia
+using ADTypes
+
+# ReverseDiff without tape compilation
+model = compile(model_def, data; adtype=AutoReverseDiff(compile=false))
+
+# ReverseDiff with compilation (equivalent to :ReverseDiff)
+model = compile(model_def, data; adtype=AutoReverseDiff(compile=true))
+```
+
+### Performance Considerations
+
+- **ReverseDiff with compilation** (`:ReverseDiff`) is recommended for most models, especially those with many parameters. Compilation adds a one-time overhead but significantly speeds up subsequent gradient evaluations.
+
+- **ForwardDiff** (`:ForwardDiff`) is often faster for models with few parameters (< 20), as it avoids tape construction overhead.
+
+- **Tape compilation trade-off**: While `AutoReverseDiff(compile=true)` has higher initial compilation time, it provides faster gradient evaluations during sampling. For quick prototyping or models that will only be sampled a few times, `AutoReverseDiff(compile=false)` may be preferable.
+
+### Compatibility
+
+All models compiled with an `adtype` implement the full [`LogDensityProblems.jl`](https://www.tamaspapp.eu/LogDensityProblems.jl/dev/) interface, making them compatible with:
+
+- [`AdvancedHMC.jl`](https://github.com/TuringLang/AdvancedHMC.jl) — NUTS and HMC samplers
+- Any other sampler that works with the LogDensityProblems interface
+
+The gradient computation is prepared during model compilation for optimal performance during sampling.
+
 ## More Examples
 
 We have transcribed all the examples from the first volume of the BUGS Examples ([original](https://www.multibugs.org/examples/latest/VolumeI.html) and [transcribed](https://github.com/TuringLang/JuliaBUGS.jl/tree/main/JuliaBUGS/src/BUGSExamples/Volume_1)). All programs and data are included, and can be compiled using the steps described in the tutorial above.