greyjack 0.4.6

Rust version of GreyJack Solver for constraint continuous, integer, mixed integer optimization problems
Documentation


use crate::score_calculation::score_requesters::VariablesManager;
use super::Mover;
use super::MetaheuristicBaseTrait;
use crate::score_calculation::scores::ScoreTrait;
use crate::agents::base::Individual;
use ndarray::Array1;
use ndarray_rand::RandomExt;
use rand_distr::num_traits::ToPrimitive;
use std::ops::AddAssign;
use std::fmt::Debug;

use rand::SeedableRng;
use rand::rngs::StdRng;
use rand_distr::{Distribution, Uniform};

use super::metaheuristic_kinds_and_names::{MetaheuristicKind, MetaheuristicNames};
use crate::utils::math_utils;
use std::collections::HashMap;
use std::collections::VecDeque;
use std::collections::HashSet;
use std::cmp::max;



pub struct TabuSearchBase {

    pub neighbours_count: usize,
    pub tabu_entity_rate: f64,

    pub metaheuristic_kind: MetaheuristicKind,
    pub metaheuristic_name: MetaheuristicNames,

    pub discrete_ids: Option<Vec<usize>>,
    pub mover: Mover,
}

impl TabuSearchBase {

    pub fn new(
        neighbours_count: usize,
        tabu_entity_rate: f64,
        mutation_rate_multiplier: Option<f64>,
        move_probas: Option<Vec<f64>>,
        semantic_groups_map: HashMap<String, Vec<usize>>,
        discrete_ids: Option<Vec<usize>>,
    ) -> Self {

        let current_mutation_rate_multiplier;
        match mutation_rate_multiplier {
            Some(x) => current_mutation_rate_multiplier = mutation_rate_multiplier.unwrap(),
            None => current_mutation_rate_multiplier = 0.0,
        }
        let mut group_mutation_rates_map: HashMap<String, f64> = HashMap::new();
        for group_name in semantic_groups_map.keys() {
            let group_size = semantic_groups_map[group_name].len();
            let current_group_mutation_rate = current_mutation_rate_multiplier * (1.0 / (group_size as f64));
            group_mutation_rates_map.insert(group_name.clone(), current_group_mutation_rate);
        }

        Self {
            neighbours_count: neighbours_count,
            tabu_entity_rate: tabu_entity_rate,

            metaheuristic_kind: MetaheuristicKind::LocalSearch,
            metaheuristic_name: MetaheuristicNames::TabuSearch,

            discrete_ids: discrete_ids.clone(),
            mover: Mover::new(tabu_entity_rate, HashMap::new(), HashMap::new(), HashMap::new(), group_mutation_rates_map, move_probas),
        }
    }

}

impl<ScoreType> MetaheuristicBaseTrait<ScoreType> for TabuSearchBase
where ScoreType: ScoreTrait + Clone + AddAssign + PartialEq + PartialOrd + Ord + Debug + Send {

    fn sample_candidates_plain(
            &mut self, 
            population: &mut Vec<Individual<ScoreType>>, 
            current_top_individual: &Individual<ScoreType>,
            variables_manager: &VariablesManager
        ) -> Vec<Array1<f64>> {

        if self.mover.tabu_entity_size_map.len() == 0 {
            let semantic_groups_map = variables_manager.semantic_groups_map.clone();
            for (group_name, group_ids) in semantic_groups_map {
                self.mover.tabu_ids_sets_map.insert(group_name.clone(), HashSet::new());
                self.mover.tabu_entity_size_map.insert(group_name.clone(), max((self.tabu_entity_rate * (group_ids.len().to_f64().unwrap())).ceil() as usize, 1));
                self.mover.tabu_ids_vecdeque_map.insert(group_name.clone(), VecDeque::new());
            }
        }

        let current_best_candidate = population[0].variable_values.clone();
        let mut candidates: Vec<Array1<f64>> = (0..self.neighbours_count).into_iter().map(|i| {
            let (changed_candidate, changed_columns, _) = self.mover.do_move(&current_best_candidate, variables_manager, false);
            let mut candidate = changed_candidate.unwrap();
            variables_manager.fix_variables(&mut candidate, changed_columns);
            candidate
        }).collect();

        return candidates;
    }

    fn sample_candidates_incremental(
        &mut self,
        population: &mut Vec<Individual<ScoreType>>, 
        current_top_individual: &Individual<ScoreType>,
        variables_manager: &VariablesManager
    ) -> (Array1<f64>, Vec<Vec<(usize, f64)>>) {

        if self.mover.tabu_entity_size_map.len() == 0 {
            let semantic_groups_map = variables_manager.semantic_groups_map.clone();
            for (group_name, group_ids) in semantic_groups_map {
                self.mover.tabu_ids_sets_map.insert(group_name.clone(), HashSet::new());
                self.mover.tabu_entity_size_map.insert(group_name.clone(), max((self.tabu_entity_rate * (group_ids.len().to_f64().unwrap())).ceil() as usize, 1));
                self.mover.tabu_ids_vecdeque_map.insert(group_name.clone(), VecDeque::new());
            }
        }

        let current_best_candidate = population[0].variable_values.clone();
        let mut deltas: Vec<Vec<(usize, f64)>> = (0..self.neighbours_count).into_iter().map(|i| {

            let (_, changed_columns, candidate_deltas) = self.mover.do_move(&current_best_candidate, variables_manager, true);
            let mut candidate_deltas = candidate_deltas.unwrap();
            variables_manager.fix_deltas(&mut candidate_deltas, changed_columns.clone());
            let changed_columns = changed_columns.unwrap();
            let candidate_deltas: Vec<(usize, f64)> = changed_columns.iter().zip(candidate_deltas.iter()).map(|(col_id, delta_value)| (*col_id, *delta_value)).collect();
            candidate_deltas
        }).collect();

        return (current_best_candidate.clone(), deltas);


    }

    fn build_updated_population(
        &mut self, 
        current_population: &Vec<Individual<ScoreType>>, 
        candidates: &mut Vec<Individual<ScoreType>>
        ) -> Vec<Individual<ScoreType>> {
        
        candidates.sort();
        let new_population:Vec<Individual<ScoreType>>;
        let best_candidate = candidates[0].clone();
        if best_candidate.score <= current_population[0].score {
            new_population = vec![best_candidate; 1];
        } else {
            new_population = current_population.clone();
        }

        return new_population;
    }

    fn build_updated_population_incremental(
            &mut self, 
            current_population: &Vec<Individual<ScoreType>>, 
            sample: &mut Array1<f64>,
            deltas: Vec<Vec<(usize, f64)>>,
            scores: Vec<ScoreType>,
        ) -> Vec<Individual<ScoreType>> {
        

        let best_score_id: usize = scores
            .iter()
            .enumerate()
            .min_by(|(_, a), (_, b)| a.cmp(b))
            .map(|(index, _)| index)
            .unwrap();
        let best_score = scores[best_score_id].clone();    
        let new_population:Vec<Individual<ScoreType>>;
        if best_score <= current_population[0].score {
            let best_deltas = &deltas[best_score_id];
            for (var_id, new_value) in best_deltas {
                sample[*var_id] = *new_value;
            }
            let best_candidate = Individual::new(sample.clone(), best_score);
            new_population = vec![best_candidate; 1];
        } else {
            new_population = current_population.clone();
        }

        return new_population;


    }

    fn get_metaheuristic_kind(&self) -> MetaheuristicKind {
        self.metaheuristic_kind.clone()
    }

    fn get_metaheuristic_name(&self) -> MetaheuristicNames {
        self.metaheuristic_name.clone()
    }
}

unsafe impl Send for TabuSearchBase {}