optirs-learned 0.3.1

OptiRS learned optimizers and meta-learning
Documentation
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use std::fmt::Debug;
// Evolutionary search algorithms for neural architecture search
//
// This module implements evolutionary algorithms for automatically discovering
// optimal optimizer architectures through genetic programming approaches.

#[allow(dead_code)]

use scirs2_core::ndarray::{Array1, Array2};
use scirs2_core::numeric::Float;
use std::collections::{HashMap, HashSet, VecDeque};

use crate::error::{OptimError, Result};

/// Evolutionary search configuration
#[derive(Debug, Clone)]
pub struct EvolutionaryConfig<T: Float + Debug + Send + Sync + 'static> {
    /// Population size
    pub population_size: usize,
    
    /// Number of generations
    pub num_generations: usize,
    
    /// Mutation rate
    pub mutation_rate: T,
    
    /// Crossover rate
    pub crossover_rate: T,
    
    /// Elitism ratio (fraction of best individuals to preserve)
    pub elitism_ratio: T,
    
    /// Tournament size for selection
    pub tournament_size: usize,
    
    /// Architecture complexity penalty
    pub complexity_penalty: T,
    
    /// Maximum architecture depth
    pub max_depth: usize,
    
    /// Maximum number of parameters
    pub max_parameters: usize,
}

/// Individual in the evolutionary population
#[derive(Debug, Clone)]
pub struct Individual<T: Float + Debug + Send + Sync + 'static> {
    /// Architecture specification
    pub architecture: ArchitectureSpecification<T>,
    
    /// Fitness score
    pub fitness: T,
    
    /// Age (number of generations survived)
    pub age: usize,
    
    /// Performance metrics
    pub performance_metrics: PerformanceMetrics<T>,
    
    /// Generation when created
    pub birth_generation: usize,
}

/// Architecture specification for evolved architectures
#[derive(Debug, Clone)]
pub struct ArchitectureSpecification<T: Float + Debug + Send + Sync + 'static> {
    /// Layer specifications
    pub layers: Vec<LayerSpec<T>>,
    
    /// Connection topology
    pub connections: ConnectionTopology,
    
    /// Global architecture parameters
    pub global_params: HashMap<String, T>,
    
    /// Estimated parameter count
    pub parameter_count: usize,
    
    /// Estimated FLOPs
    pub estimated_flops: u64,
}

/// Layer specification
#[derive(Debug, Clone)]
pub struct LayerSpec<T: Float + Debug + Send + Sync + 'static> {
    /// Layer type
    pub layer_type: LayerType,
    
    /// Input dimensions
    pub input_dims: Vec<usize>,
    
    /// Output dimensions
    pub output_dims: Vec<usize>,
    
    /// Layer-specific parameters
    pub parameters: HashMap<String, LayerParameter<T>>,
    
    /// Layer identifier
    pub id: String,
}

/// Layer types for evolutionary search
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub enum LayerType {
    /// Dense/Linear layer
    Dense,
    /// Convolutional layer
    Conv1D,
    /// LSTM layer
    LSTM,
    /// GRU layer
    GRU,
    /// Attention layer
    Attention,
    /// Normalization layer
    BatchNorm,
    /// Dropout layer
    Dropout,
    /// Activation layer
    Activation,
    /// Custom optimizer layer
    OptimizerLayer,
}

/// Layer parameters
#[derive(Debug, Clone)]
pub enum LayerParameter<T: Float + Debug + Send + Sync + 'static> {
    /// Integer parameter
    Integer(i64),
    /// Float parameter
    Float(T),
    /// Boolean parameter
    Boolean(bool),
    /// String parameter
    String(String),
    /// Array parameter
    Array(Vec<T>),
}

/// Connection topology between layers
#[derive(Debug, Clone)]
pub struct ConnectionTopology {
    /// Adjacency matrix
    pub adjacency_matrix: Array2<f32>,
    
    /// Connection types
    pub connection_types: HashMap<(usize, usize), ConnectionType>,
    
    /// Skip connections
    pub skip_connections: Vec<(usize, usize)>,
}

/// Connection types between layers
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub enum ConnectionType {
    /// Standard forward connection
    Forward,
    /// Residual connection
    Residual,
    /// Dense connection (all previous layers)
    Dense,
    /// Attention connection
    Attention,
}

/// Performance metrics for individuals
#[derive(Debug, Clone)]
pub struct PerformanceMetrics<T: Float + Debug + Send + Sync + 'static> {
    /// Training performance
    pub training_performance: T,
    
    /// Validation performance
    pub validation_performance: T,
    
    /// Convergence speed
    pub convergence_speed: T,
    
    /// Memory efficiency
    pub memory_efficiency: T,
    
    /// Computational efficiency
    pub computational_efficiency: T,
    
    /// Generalization score
    pub generalization: T,
}

/// Evolutionary algorithm for architecture search
#[derive(Debug)]
pub struct EvolutionarySearcher<T: Float + Debug + Send + Sync + 'static> {
    /// Configuration
    config: EvolutionaryConfig<T>,
    
    /// Current population
    population: Vec<Individual<T>>,
    
    /// Best individual found so far
    best_individual: Option<Individual<T>>,
    
    /// Current generation
    current_generation: usize,
    
    /// Evolution history
    evolution_history: EvolutionHistory<T>,
    
    /// Mutation operators
    mutation_operators: Vec<MutationOperator>,
    
    /// Crossover operators
    crossover_operators: Vec<CrossoverOperator>,
    
    /// Selection strategy
    selection_strategy: SelectionStrategy,
}

/// Evolution history tracking
#[derive(Debug, Clone)]
pub struct EvolutionHistory<T: Float + Debug + Send + Sync + 'static> {
    /// Best fitness per generation
    pub best_fitness_history: Vec<T>,
    
    /// Average fitness per generation
    pub average_fitness_history: Vec<T>,
    
    /// Population diversity per generation
    pub diversity_history: Vec<T>,
    
    /// Performance improvements
    pub improvements: Vec<(usize, T)>,
}

/// Mutation operators
#[derive(Debug, Clone, Copy)]
pub enum MutationOperator {
    /// Add new layer
    AddLayer,
    /// Remove existing layer
    RemoveLayer,
    /// Modify layer parameters
    ModifyParameters,
    /// Change layer type
    ChangeLayerType,
    /// Modify connections
    ModifyConnections,
    /// Add skip connection
    AddSkipConnection,
    /// Remove skip connection
    RemoveSkipConnection,
}

/// Crossover operators
#[derive(Debug, Clone, Copy)]
pub enum CrossoverOperator {
    /// Single-point crossover
    SinglePoint,
    /// Multi-point crossover
    MultiPoint,
    /// Uniform crossover
    Uniform,
    /// Layer-wise crossover
    LayerWise,
    /// Connection-wise crossover
    ConnectionWise,
}

/// Selection strategies
#[derive(Debug, Clone, Copy)]
pub enum SelectionStrategy {
    /// Tournament selection
    Tournament,
    /// Roulette wheel selection
    RouletteWheel,
    /// Rank-based selection
    RankBased,
    /// Elite selection
    Elite,
}

impl<T: Float + Debug + Default + Clone + Send + Sync + 'static> EvolutionarySearcher<T> {
    /// Create new evolutionary searcher
    pub fn new(config: EvolutionaryConfig<T>) -> Result<Self> {
        Ok(Self {
            config,
            population: Vec::new(),
            best_individual: None,
            current_generation: 0,
            evolution_history: EvolutionHistory::new(),
            mutation_operators: vec![
                MutationOperator::AddLayer,
                MutationOperator::RemoveLayer,
                MutationOperator::ModifyParameters,
                MutationOperator::ChangeLayerType,
                MutationOperator::ModifyConnections,
            ],
            crossover_operators: vec![
                CrossoverOperator::SinglePoint,
                CrossoverOperator::LayerWise,
                CrossoverOperator::ConnectionWise,
            ],
            selection_strategy: SelectionStrategy::Tournament,
        })
    }

    /// Initialize population with random individuals
    pub fn initialize_population(&mut self) -> Result<()> {
        self.population.clear();
        
        for i in 0..self.config.population_size {
            let individual = self.create_random_individual(i)?;
            self.population.push(individual);
        }
        
        Ok(())
    }

    /// Run evolutionary search for specified number of generations
    pub fn search(&mut self, fitness_fn: &dyn Fn(&ArchitectureSpecification<T>) -> Result<T>) -> Result<Individual<T>> {
        // Initialize population if empty
        if self.population.is_empty() {
            self.initialize_population()?;
        }
        
        // Evaluate initial population
        self.evaluate_population(fitness_fn)?;
        
        // Evolution loop
        for generation in 0..self.config.num_generations {
            self.current_generation = generation;
            
            // Selection
            let selected = self.selection()?;
            
            // Crossover and mutation
            let mut offspring = self.crossover_and_mutation(&selected)?;
            
            // Evaluate offspring
            for individual in &mut offspring {
                individual.fitness = fitness_fn(&individual.architecture)?;
                individual.performance_metrics = self.evaluate_performance_metrics(&individual.architecture)?;
            }
            
            // Survivor selection (elitism + replacement)
            self.survivor_selection(&mut offspring)?;
            
            // Update statistics
            self.update_evolution_history()?;
            
            // Check for improvement
            if let Some(ref best) = self.best_individual {
                println!("Generation {}: Best fitness = {}", generation, best.fitness.to_f64().unwrap_or(0.0));
            }
        }
        
        self.best_individual.clone().ok_or_else(|| 
            OptimError::SearchFailed("No valid individuals found".to_string())
        )
    }

    /// Create a random individual
    fn create_random_individual(&self, id: usize) -> Result<Individual<T>> {
        use scirs2_core::random::Rng;
        let mut rng = scirs2_core::random::thread_rng();
        
        // Random number of layers (between 2 and max_depth)
        let num_layers = rng.gen_range(2..=self.config.max_depth.min(10));
        let mut layers = Vec::new();
        
        for i in 0..num_layers {
            let layer = self.create_random_layer(i)?;
            layers.push(layer);
        }
        
        let connections = self.create_random_connections(num_layers)?;
        let parameter_count = self.estimate_parameters(&layers);
        
        let architecture = ArchitectureSpecification {
            layers,
            connections,
            global_params: HashMap::new(),
            parameter_count,
            estimated_flops: parameter_count as u64 * 1000, // Rough estimation
        };
        
        Ok(Individual {
            architecture,
            fitness: T::zero(),
            age: 0,
            performance_metrics: PerformanceMetrics::default(),
            birth_generation: self.current_generation,
        })
    }

    /// Create a random layer specification
    fn create_random_layer(&self, layer_id: usize) -> Result<LayerSpec<T>> {
        use scirs2_core::random::Rng;
        let mut rng = scirs2_core::random::thread_rng();
        
        let layer_types = vec![
            LayerType::Dense,
            LayerType::Conv1D,
            LayerType::LSTM,
            LayerType::Attention,
            LayerType::BatchNorm,
        ];
        
        let layer_type = layer_types[rng.gen_range(0..layer_types.len())];
        let mut parameters = HashMap::new();
        
        match layer_type {
            LayerType::Dense => {
                let input_size = if layer_id == 0 { 128 } else { rng.gen_range(32..512) };
                let output_size = rng.gen_range(32..512);
                parameters.insert("input_size".to_string(), LayerParameter::Integer(input_size));
                parameters.insert("output_size".to_string(), LayerParameter::Integer(output_size));
            }
            LayerType::LSTM => {
                let hidden_size = rng.gen_range(64..256);
                parameters.insert("hidden_size".to_string(), LayerParameter::Integer(hidden_size));
                parameters.insert("num_layers".to_string(), LayerParameter::Integer(1));
            }
            LayerType::Attention => {
                let hidden_dim = rng.gen_range(64..256);
                let num_heads = rng.gen_range(4..16);
                parameters.insert("hidden_dim".to_string(), LayerParameter::Integer(hidden_dim));
                parameters.insert("num_heads".to_string(), LayerParameter::Integer(num_heads));
            }
            _ => {}
        }
        
        Ok(LayerSpec {
            layer_type,
            input_dims: vec![128], // Simplified
            output_dims: vec![128],
            parameters,
            id: format!("layer_{}", layer_id),
        })
    }

    /// Create random connections between layers
    fn create_random_connections(&self, num_layers: usize) -> Result<ConnectionTopology> {
        use scirs2_core::random::Rng;
        let mut rng = scirs2_core::random::thread_rng();
        
        let mut adjacency_matrix = Array2::zeros((num_layers, num_layers));
        let mut connection_types = HashMap::new();
        let mut skip_connections = Vec::new();
        
        // Sequential connections
        for i in 0..num_layers-1 {
            adjacency_matrix[[i, i+1]] = 1.0;
            connection_types.insert((i, i+1), ConnectionType::Forward);
        }
        
        // Random skip connections
        let num_skip = rng.gen_range(0..num_layers/2);
        for _ in 0..num_skip {
            let from = rng.gen_range(0..num_layers-2);
            let to = rng.gen_range(from+2..num_layers);
            if adjacency_matrix[[from, to]] == 0.0 {
                adjacency_matrix[[from, to]] = 1.0;
                connection_types.insert((from, to), ConnectionType::Residual);
                skip_connections.push((from, to));
            }
        }
        
        Ok(ConnectionTopology {
            adjacency_matrix,
            connection_types,
            skip_connections,
        })
    }

    /// Estimate parameter count for layers
    fn estimate_parameters(&self, layers: &[LayerSpec<T>]) -> usize {
        layers.iter().map(|layer| {
            match layer.layer_type {
                LayerType::Dense => {
                    if let (Some(LayerParameter::Integer(input)), Some(LayerParameter::Integer(output))) =
                        (layer.parameters.get("input_size"), layer.parameters.get("output_size")) {
                        (*input as usize) * (*output as usize) + (*output as usize)
                    } else { 1000 }
                }
                LayerType::LSTM => {
                    if let Some(LayerParameter::Integer(hidden)) = layer.parameters.get("hidden_size") {
                        4 * (*hidden as usize) * (*hidden as usize) // Simplified LSTM parameter count
                    } else { 10000 }
                }
                LayerType::Attention => {
                    if let Some(LayerParameter::Integer(hidden)) = layer.parameters.get("hidden_dim") {
                        3 * (*hidden as usize) * (*hidden as usize) // Q, K, V matrices
                    } else { 5000 }
                }
                _ => 100 // Default small size
            }
        }).sum()
    }

    /// Evaluate fitness for all individuals in population
    fn evaluate_population(&mut self, fitness_fn: &dyn Fn(&ArchitectureSpecification<T>) -> Result<T>) -> Result<()> {
        for individual in &mut self.population {
            individual.fitness = fitness_fn(&individual.architecture)?;
            individual.performance_metrics = self.evaluate_performance_metrics(&individual.architecture)?;
        }
        
        // Update best individual
        if let Some(best) = self.population.iter().max_by(|a, b| 
            a.fitness.partial_cmp(&b.fitness).unwrap_or(std::cmp::Ordering::Equal)) {
            self.best_individual = Some(best.clone());
        }
        
        Ok(())
    }

    /// Selection phase of evolutionary algorithm
    fn selection(&self) -> Result<Vec<Individual<T>>> {
        match self.selection_strategy {
            SelectionStrategy::Tournament => self.tournament_selection(),
            SelectionStrategy::RouletteWheel => self.roulette_wheel_selection(),
            SelectionStrategy::RankBased => self.rank_based_selection(),
            SelectionStrategy::Elite => self.elite_selection(),
        }
    }

    /// Tournament selection
    fn tournament_selection(&self) -> Result<Vec<Individual<T>>> {
        use scirs2_core::random::Rng;
        let mut rng = scirs2_core::random::thread_rng();
        let mut selected = Vec::new();
        
        for _ in 0..self.config.population_size {
            let mut tournament = Vec::new();
            for _ in 0..self.config.tournament_size {
                let idx = rng.gen_range(0..self.population.len());
                tournament.push(&self.population[idx]);
            }
            
            let winner = tournament.into_iter().max_by(|a, b|
                a.fitness.partial_cmp(&b.fitness).unwrap_or(std::cmp::Ordering::Equal)
            ).expect("unwrap failed");
            
            selected.push(winner.clone());
        }
        
        Ok(selected)
    }

    /// Simplified selection methods (placeholders for full implementation)
    fn roulette_wheel_selection(&self) -> Result<Vec<Individual<T>>> {
        // Simplified: just return population
        Ok(self.population.clone())
    }

    fn rank_based_selection(&self) -> Result<Vec<Individual<T>>> {
        // Simplified: just return population
        Ok(self.population.clone())
    }

    fn elite_selection(&self) -> Result<Vec<Individual<T>>> {
        let mut sorted = self.population.clone();
        sorted.sort_by(|a, b| b.fitness.partial_cmp(&a.fitness).unwrap_or(std::cmp::Ordering::Equal));
        Ok(sorted.into_iter().take(self.config.population_size).collect())
    }

    /// Crossover and mutation phase
    fn crossover_and_mutation(&self, selected: &[Individual<T>]) -> Result<Vec<Individual<T>>> {
        use scirs2_core::random::Rng;
        let mut rng = scirs2_core::random::thread_rng();
        let mut offspring = Vec::new();
        
        for i in (0..selected.len()).step_by(2) {
            let parent1 = &selected[i];
            let parent2 = if i + 1 < selected.len() { &selected[i + 1] } else { &selected[0] };
            
            let (mut child1, mut child2) = if rng.random::<f64>() < self.config.crossover_rate.to_f64().unwrap_or(0.7) {
                self.crossover(parent1, parent2)?
            } else {
                (parent1.clone(), parent2.clone())
            };
            
            // Mutation
            if rng.random::<f64>() < self.config.mutation_rate.to_f64().unwrap_or(0.1) {
                self.mutate(&mut child1)?;
            }
            if rng.random::<f64>() < self.config.mutation_rate.to_f64().unwrap_or(0.1) {
                self.mutate(&mut child2)?;
            }
            
            offspring.push(child1);
            if offspring.len() < self.config.population_size {
                offspring.push(child2);
            }
        }
        
        Ok(offspring)
    }

    /// Simple crossover (layer-wise)
    fn crossover(&self, parent1: &Individual<T>, parent2: &Individual<T>) -> Result<(Individual<T>, Individual<T>)> {
        use scirs2_core::random::Rng;
        let mut rng = scirs2_core::random::thread_rng();
        
        let mut child1 = parent1.clone();
        let mut child2 = parent2.clone();
        
        // Simple single-point crossover on layers
        let min_layers = parent1.architecture.layers.len().min(parent2.architecture.layers.len());
        if min_layers > 1 {
            let crossover_point = rng.gen_range(1..min_layers);
            
            // Swap layer segments
            for i in crossover_point..min_layers {
                if i < child1.architecture.layers.len() && i < parent2.architecture.layers.len() {
                    child1.architecture.layers[i] = parent2.architecture.layers[i].clone();
                }
                if i < child2.architecture.layers.len() && i < parent1.architecture.layers.len() {
                    child2.architecture.layers[i] = parent1.architecture.layers[i].clone();
                }
            }
        }
        
        Ok((child1, child2))
    }

    /// Mutation operation
    fn mutate(&self, individual: &mut Individual<T>) -> Result<()> {
        use scirs2_core::random::Rng;
        let mut rng = scirs2_core::random::thread_rng();
        
        let mutation_op = self.mutation_operators[rng.gen_range(0..self.mutation_operators.len())];
        
        match mutation_op {
            MutationOperator::AddLayer => {
                if individual.architecture.layers.len() < self.config.max_depth {
                    let new_layer = self.create_random_layer(individual.architecture.layers.len())?;
                    individual.architecture.layers.push(new_layer);
                }
            }
            MutationOperator::RemoveLayer => {
                if individual.architecture.layers.len() > 2 {
                    let idx = rng.gen_range(1..individual.architecture.layers.len()-1);
                    individual.architecture.layers.remove(idx);
                }
            }
            MutationOperator::ModifyParameters => {
                if !individual.architecture.layers.is_empty() {
                    let layer_idx = rng.gen_range(0..individual.architecture.layers.len());
                    self.mutate_layer_parameters(&mut individual.architecture.layers[layer_idx])?;
                }
            }
            _ => {} // Other mutations not implemented for brevity
        }
        
        individual.birth_generation = self.current_generation;
        Ok(())
    }

    /// Mutate layer parameters
    fn mutate_layer_parameters(&self, layer: &mut LayerSpec<T>) -> Result<()> {
        use scirs2_core::random::Rng;
        let mut rng = scirs2_core::random::thread_rng();
        
        match layer.layer_type {
            LayerType::Dense => {
                if let Some(LayerParameter::Integer(ref mut size)) = layer.parameters.get_mut("output_size") {
                    *size = rng.gen_range(32..512);
                }
            }
            LayerType::LSTM => {
                if let Some(LayerParameter::Integer(ref mut hidden)) = layer.parameters.get_mut("hidden_size") {
                    *hidden = rng.gen_range(64..256);
                }
            }
            LayerType::Attention => {
                if let Some(LayerParameter::Integer(ref mut heads)) = layer.parameters.get_mut("num_heads") {
                    *heads = rng.gen_range(4..16);
                }
            }
            _ => {}
        }
        
        Ok(())
    }

    /// Survivor selection (combine parents and offspring, keep best)
    fn survivor_selection(&mut self, offspring: &mut Vec<Individual<T>>) -> Result<()> {
        // Elitism: keep best individuals from current population
        let elite_count = (self.config.elitism_ratio * scirs2_core::numeric::NumCast::from(self.config.population_size as f64).unwrap_or_else(|| T::zero())).to_usize().unwrap_or(1);
        
        let mut combined = self.population.clone();
        combined.append(offspring);
        
        // Sort by fitness (descending)
        combined.sort_by(|a, b| b.fitness.partial_cmp(&a.fitness).unwrap_or(std::cmp::Ordering::Equal));
        
        // Keep top individuals
        self.population = combined.into_iter().take(self.config.population_size).collect();
        
        // Update ages
        for individual in &mut self.population {
            individual.age += 1;
        }
        
        Ok(())
    }

    /// Update evolution history and statistics
    fn update_evolution_history(&mut self) -> Result<()> {
        if self.population.is_empty() {
            return Ok(());
        }
        
        let best_fitness = self.population.iter()
            .map(|ind| ind.fitness)
            .max_by(|a, b| a.partial_cmp(b).unwrap_or(std::cmp::Ordering::Equal))
            .unwrap_or(T::zero());
        
        let avg_fitness = self.population.iter().map(|ind| ind.fitness).fold(T::zero(), |acc, f| acc + f) /
            T::from(self.population.len() as f64).expect("unwrap failed");
        
        let diversity = self.calculate_population_diversity()?;
        
        self.evolution_history.best_fitness_history.push(best_fitness);
        self.evolution_history.average_fitness_history.push(avg_fitness);
        self.evolution_history.diversity_history.push(diversity);
        
        Ok(())
    }

    /// Calculate population diversity
    fn calculate_population_diversity(&self) -> Result<T> {
        // Simplified diversity calculation based on architecture differences
        if self.population.len() < 2 {
            return Ok(T::zero());
        }
        
        let mut total_difference = T::zero();
        let mut comparisons = 0;
        
        for i in 0..self.population.len() {
            for j in i+1..self.population.len() {
                let diff = self.calculate_architecture_difference(
                    &self.population[i].architecture,
                    &self.population[j].architecture
                );
                total_difference = total_difference + diff;
                comparisons += 1;
            }
        }
        
        Ok(total_difference / scirs2_core::numeric::NumCast::from(comparisons as f64).unwrap_or_else(|| T::zero()))
    }

    /// Calculate difference between two architectures
    fn calculate_architecture_difference(&self, arch1: &ArchitectureSpecification<T>, arch2: &ArchitectureSpecification<T>) -> T {
        let layer_diff = T::from((arch1.layers.len() as i32 - arch2.layers.len() as i32).abs() as f64).expect("unwrap failed");
        let param_diff = T::from((arch1.parameter_count as i32 - arch2.parameter_count as i32).abs() as f64).expect("unwrap failed") / scirs2_core::numeric::NumCast::from(1000.0).unwrap_or_else(|| T::zero());
        
        layer_diff + param_diff
    }

    /// Evaluate performance metrics for an architecture
    fn evaluate_performance_metrics(&self, architecture: &ArchitectureSpecification<T>) -> Result<PerformanceMetrics<T>> {
        // Simplified performance evaluation
        let complexity = scirs2_core::numeric::NumCast::from(architecture.parameter_count as f64).unwrap_or_else(|| T::zero()) / scirs2_core::numeric::NumCast::from(1000000.0).unwrap_or_else(|| T::zero()); // In millions
        let efficiency = T::one() / (T::one() + complexity);
        
        Ok(PerformanceMetrics {
            training_performance: scirs2_core::numeric::NumCast::from(0.8).unwrap_or_else(|| T::zero()) - complexity * scirs2_core::numeric::NumCast::from(0.1).unwrap_or_else(|| T::zero()),
            validation_performance: scirs2_core::numeric::NumCast::from(0.75).unwrap_or_else(|| T::zero()) - complexity * scirs2_core::numeric::NumCast::from(0.15).unwrap_or_else(|| T::zero()),
            convergence_speed: efficiency,
            memory_efficiency: efficiency,
            computational_efficiency: efficiency,
            generalization: scirs2_core::numeric::NumCast::from(0.7).unwrap_or_else(|| T::zero()),
        })
    }

    /// Get current best individual
    pub fn best_individual(&self) -> Option<&Individual<T>> {
        self.best_individual.as_ref()
    }

    /// Get evolution history
    pub fn evolution_history(&self) -> &EvolutionHistory<T> {
        &self.evolution_history
    }

    /// Get current population
    pub fn population(&self) -> &[Individual<T>] {
        &self.population
    }
}

impl<T: Float + Debug + Default + Clone + Send + Sync + 'static> EvolutionHistory<T> {
    fn new() -> Self {
        Self {
            best_fitness_history: Vec::new(),
            average_fitness_history: Vec::new(),
            diversity_history: Vec::new(),
            improvements: Vec::new(),
        }
    }
}

impl<T: Float + Debug + Default + Clone + Send + Sync + 'static> Default for PerformanceMetrics<T> {
    fn default() -> Self {
        Self {
            training_performance: T::zero(),
            validation_performance: T::zero(),
            convergence_speed: T::zero(),
            memory_efficiency: T::zero(),
            computational_efficiency: T::zero(),
            generalization: T::zero(),
        }
    }
}

impl<T: Float + Debug + Default + Clone + Send + Sync + 'static> Default for EvolutionaryConfig<T> {
    fn default() -> Self {
        Self {
            population_size: 50,
            num_generations: 100,
            mutation_rate: scirs2_core::numeric::NumCast::from(0.1).unwrap_or_else(|| T::zero()),
            crossover_rate: scirs2_core::numeric::NumCast::from(0.7).unwrap_or_else(|| T::zero()),
            elitism_ratio: scirs2_core::numeric::NumCast::from(0.1).unwrap_or_else(|| T::zero()),
            tournament_size: 3,
            complexity_penalty: scirs2_core::numeric::NumCast::from(0.01).unwrap_or_else(|| T::zero()),
            max_depth: 10,
            max_parameters: 10_000_000,
        }
    }
}

impl Default for ConnectionTopology {
    fn default() -> Self {
        Self {
            adjacency_matrix: Array2::zeros((0, 0)),
            connection_types: HashMap::new(),
            skip_connections: Vec::new(),
        }
    }
}