Getting started

intrees(model::Union{AbstractModel,DecisionForest}, X, y::AbstractVector{<:Label}; kwargs...)::DecisionList

Return a decision list which approximates the behavior of the input model on the specified supervised dataset. The set of relevant and non-redundant rules in the decision list are obtained by means of rule selection, rule pruning, and sequential covering (STEL).

References

• Deng, Houtao. "Interpreting tree ensembles with intrees." International Journal of Data Science and Analytics 7.4 (2019): 277-287.

Keyword Arguments

• prune_rules::Bool=true: access to prune or not
• pruning_s::Union{Float64,Nothing}=nothing: parameter that limits the denominator in the pruning metric calculation
• pruning_decay_threshold::Union{Float64,Nothing}=nothing: threshold used in pruning to remove or not a joint from the rule
• rule_selection_method::Symbol=:CBC: rule selection method. Currently only supports :CBC
• rule_complexity_metric::Symbol=:natoms: Metric to use for estimating a rule complexity measure
• max_rules::Int=-1: maximum number of rules in the final decision list (excluding default rule). Use -1 for unlimited rules.
• min_coverage::Union{Float64,Nothing}=nothing: minimum rule coverage for STEL
• See modalextractrules keyword arguments...

Although the method was originally presented for forests it is hereby extended to work with any symbolic models.

See also AbstractModel, DecisionList, listrules, rulemetrics.

lumen(model; config_args...) -> LumenResult
lumen(model, config::LumenConfig) -> LumenResult

Logic-driven Unified Minimal Extractor of Notions (LUMEN): Extract and minimize logical rules from decision tree models into interpretable DNF formulas.

LUMEN implements a comprehensive pipeline for converting decision tree models into interpretable logical rules. The algorithm extracts the underlying decision logic, constructs truth tables, and applies advanced minimization techniques to produce compact, human-readable rule sets.

Method Signatures

Keyword Arguments Interface

lumen(model; minimization_scheme=:mitespresso, vertical=1.0, horizontal=1.0, ...)

Convenient interface using keyword arguments with automatic config construction.

Configuration Object Interface

lumen(model, config::LumenConfig)

Advanced interface using pre-constructed configuration for complex scenarios.

Arguments

Required Arguments

• model: Decision tree model to analyze
  • Single trees: Individual decision tree models
  • Ensembles: Random forests, gradient boosting, etc.
  • Supported formats: DecisionTree.jl, SoleModels framework

Configuration (via keywords or LumenConfig)

• minimization_scheme::Symbol = :mitespresso: DNF minimization algorithm
• vertical::Float64 = 1.0: Instance coverage parameter α ∈ (0,1]
• depth::Float64 = 1.0: Depth coverage parameter δ ∈ (0,1]
• horizontal::Float64 = 1.0: Feature coverage parameter β ∈ (0,1]
• ott_mode::Bool = false: Enable memory-optimized processing
• silent::Bool = false: Suppress progress output
• return_info::Bool = true: Include detailed metadata in results

Returns

LumenResult containing:

• decision_set: Collection of minimized logical rules
• info: Metadata including statistics and unminimized rules
• processing_time: Total algorithm execution time

Algorithm Pipeline

Phase 1: Model Analysis and Rule Extraction

Input Model → Rule Extraction → Logical Rule Set

• Analyzes model structure (single tree vs ensemble)
• Extracts decision paths as logical rules
• Handles different model types with appropriate strategies

Phase 2: Alphabet Construction and Atom Processing

Logical Rules → Atom Extraction → Logical Alphabet

• Identifies atomic logical conditions
• Constructs vocabulary for formula building
• Validates feature support and operator compatibility

Phase 3: Truth Table Generation

Model + Alphabet → Truth Combinations → Labeled Examples

• Generates systematic input combinations
• Evaluates model on each combination
• Creates correspondence between inputs and outputs

Phase 4: DNF Construction and Minimization

Truth Table → DNF Formulas → Minimized Rules

• Constructs DNF formulas for each decision class
• Applies advanced minimization algorithms
• Converts back to interpretable rule format

Performance Characteristics

Computational Complexity

• Time: O(2^k × n × d) where k=features, n=instances, d=tree depth
• Space: O(k × r) where r=number of rules
• Scalability: Optimized modes available for large datasets

Memory Usage

• Standard mode: Suitable for typical datasets (< 20 features)
• Optimized mode: Memory-efficient processing for large problems
• Streaming capability: Future versions may support streaming processing

Advanced Features

Custom Processing

# Custom alphabet filtering for domain expertise
custom_filter = alphabet -> remove_irrelevant_features(alphabet)
config = LumenConfig(filteralphabetcallback = custom_filter)
result = lumen(model, config)

Performance Tuning

# Memory-optimized processing for large datasets
config = LumenConfig(ott_mode = true, vertical = 0.8)

# Speed-optimized processing with basic minimization
config = LumenConfig(minimization_scheme = :abc, silent = true)

Analysis and Debugging

# Full information retention for analysis
config = LumenConfig(return_info = true, controllo = true)
result = lumen(model, config)

# Access detailed statistics
println("Rules before minimization: _(length(result.info.unminimized_ds.rules))")
println("Rules after minimization: _(length(result.decision_set.rules))")

Error Handling

The algorithm implements comprehensive error handling:

Configuration Validation

• Parameter range checking (coverage parameters must be ∈ (0,1])
• Algorithm availability verification
• Consistency validation across parameters

Processing Errors

• Graceful handling of minimization failures
• Fallback strategies for problematic formulas
• Detailed error reporting with context

Model Compatibility

• Automatic detection of supported model types
• Clear error messages for unsupported formats
• Suggestions for model preprocessing

Examples

Basic Usage

# Simple rule extraction with default settings
model = build_tree(X, y)
result = lumen(model)
println("Extracted _(length(result.decision_set.rules)) rules")

Advanced Configuration

# Customized processing for complex scenarios
config = LumenConfig(
    minimization_scheme = :boom,        # Aggressive minimization
    vertical = 0.9,                     # High instance coverage
    depth = 0.7,                        # Moderate depth coverage
    horizontal = 0.8,                   # Moderate feature coverage
    ott_mode = true,                    # Memory optimization
    return_info = true                  # Full information retention
)
result = lumen(large_ensemble, config)

Performance Analysis

# Detailed performance and quality analysis
result = lumen(model, LumenConfig(return_info = true))

# Analyze minimization effectiveness
stats = result.info.vectPrePostNumber
total_reduction = sum(pre - post for (pre, post) in stats)
avg_compression = mean(pre / post for (pre, post) in stats)

println("Total term reduction: total_reduction")
println("Average compression ratio: (round(avg_compression, digits=2))x")
println("Processing time: _(result.processing_time) seconds")

Implementation Notes

Design Principles

1. Modularity: Each phase is independently testable and extensible
2. Configurability: Extensive customization without code modification
3. Performance: Multiple optimization strategies for different scenarios
4. Robustness: Comprehensive error handling and validation
5. Usability: Clean interfaces with sensible defaults

Extensibility Points

• New minimization algorithms: Add via Val() dispatch system
• Custom model types: Extend rule extraction strategies
• Domain-specific processing: Custom alphabet filters and apply functions
• Output formats: Additional result formatters and exporters

See also: LumenConfig, LumenResult, extract_rules, minimize_formula

batrees(f; dataset_name="iris", num_trees=10, max_depth=10, dsOutput=true)

Builds and trains a set of binary decision trees OR using the specified function f.

Arguments

• f: An SoleForest.
• dataset_name::String: The name of the dataset to be used. Default is "iris".
• num_trees::Int: The number of trees to be built. Default is 10.
• max_depth::Int: The maximum depth of each tree. Default is 10.
• dsOutput::Bool: A flag indicating whether to return the dsStruct output. Default is true. if false, returns the result single tree.

Returns

• If dsOutput is true, returns the result is in DecisionSet ds.
• If dsOutput is false, returns the result is SoleTree t`.

Example

refne(m, Xmin, Xmax; L=100, perc=1.0, max_depth=-1, n_subfeatures=-1, 
      partial_sampling=0.7, min_samples_leaf=5, min_samples_split=2, 
      min_purity_increase=0.0, seed=3)

Extract interpretable rules from a trained neural network ensemble using decision tree approximation.

This implementation follows the REFNE-a (Rule Extraction From Neural Network Ensemble) algorithm, which approximates complex neural network behavior with an interpretable decision tree model.

Arguments

• m: Trained neural network model to extract rules from
• Xmin: Minimum values for each input feature
• Xmax: Maximum values for each input feature
• L: Number of samples to generate in the synthetic dataset (default: 100)
• perc: Percentage of generated samples to use (default: 1.0)
• max_depth: Maximum depth of the decision tree (default: -1, unlimited)
• n_subfeatures: Number of features to consider at each split (default: -1, all)
• partial_sampling: Fraction of samples used for each tree (default: 0.7)
• min_samples_leaf: Minimum number of samples required at a leaf node (default: 5)
• min_samples_split: Minimum number of samples required to split a node (default: 2)
• min_purity_increase: Minimum purity increase required for a split (default: 0.0)
• seed: Random seed for reproducibility (default: 3)

Returns

• A forest-decision trees representing the extracted rules

Description

The algorithm works by:

1. Generating a synthetic dataset spanning the input space
2. Using the neural network to label these samples
3. Training a decision tree to approximate the neural network's behavior

References

• Zhi-Hua, Zhou, et al. Extracting Symbolic Rules from Trained Neural Network Ensembles

Example

```julia model = loaddecisiontree_model() refne(model, Xmin, Xmax)

See also AbstractModel, DecisionList, listrules, rulemetrics.

• Mark W. Craven, et al. "Extracting Thee-Structured Representations of Thained Networks"