1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321
//! This crate exposes a generalized hyper heuristics and some helper functionality which can be
//! used to build a solver for optimization problems.
//!
//!
//! # Examples
//!
//! This example demonstrates the usage of example models and heuristics to minimize Rosenbrock function.
//! For the sake of minimalism, there is a pre-built solver and heuristic operator models. Check
//! example module to see how to use functionality of the crate for an arbitrary domain.
//!
//! ```
//! # use std::sync::Arc;
//! use rosomaxa::prelude::*;
//! use rosomaxa::example::*;
//!
//! let random = Arc::new(DefaultRandom::default());
//! // examples of heuristic operator, they are domain specific. Essentially, heuristic operator
//! // is responsible to produce a new, potentially better solution from the given one.
//! let noise_op = VectorHeuristicOperatorMode::JustNoise(Noise::new_with_ratio(1., (-0.1, 0.1), random));
//! let delta_op = VectorHeuristicOperatorMode::JustDelta(-0.1..0.1);
//! let delta_power_op = VectorHeuristicOperatorMode::JustDelta(-0.5..0.5);
//!
//! // add some configuration and run the solver
//! let (solutions, _) = Solver::default()
//! .with_fitness_fn(create_rosenbrock_function())
//! .with_init_solutions(vec![vec![2., 2.]])
//! .with_search_operator(noise_op, "noise", 1.)
//! .with_search_operator(delta_op, "delta", 0.2)
//! .with_diversify_operator(delta_power_op)
//! .with_termination(Some(5), Some(1000), None, None)
//! .solve()
//! .expect("cannot build and use solver");
//!
//! // expecting at least one solution with fitness close to 0
//! assert_eq!(solutions.len(), 1);
//! let (_, fitness) = solutions.first().unwrap();
//! assert!(*fitness < 0.001);
//!
//! # Ok::<(), GenericError>(())
//! ```
//!
#![warn(missing_docs)]
#![forbid(unsafe_code)]
#[cfg(test)]
#[path = "../tests/helpers/mod.rs"]
#[macro_use]
pub mod helpers;
pub mod algorithms;
pub mod evolution;
pub mod example;
pub mod hyper;
pub mod population;
pub mod prelude;
pub mod termination;
pub mod utils;
use crate::algorithms::math::RemedianUsize;
use crate::algorithms::nsga2::MultiObjective;
use crate::evolution::{Telemetry, TelemetryMetrics, TelemetryMode};
use crate::population::*;
use crate::utils::Timer;
use crate::utils::{Environment, GenericError};
use std::hash::Hash;
use std::sync::Arc;
/// Represents solution in population defined as actual solution.
pub trait HeuristicSolution: Send + Sync {
/// Get fitness values of a given solution.
fn fitness<'a>(&'a self) -> Box<dyn Iterator<Item = f64> + 'a>;
/// Creates a deep copy of the solution.
fn deep_copy(&self) -> Self;
}
/// Represents a heuristic objective function.
pub trait HeuristicObjective: MultiObjective + Send + Sync {}
/// Specifies a dynamically dispatched type for heuristic population.
pub type DynHeuristicPopulation<O, S> = dyn HeuristicPopulation<Objective = O, Individual = S> + Send + Sync;
/// Specifies a heuristic result type.
pub type HeuristicResult<O, S> = Result<(Box<DynHeuristicPopulation<O, S>>, Option<TelemetryMetrics>), GenericError>;
/// Represents heuristic context.
pub trait HeuristicContext: Send + Sync {
/// A heuristic objective function type.
type Objective: HeuristicObjective<Solution = Self::Solution>;
/// A heuristic solution type.
type Solution: HeuristicSolution;
/// Returns objective function used by the population.
fn objective(&self) -> &Self::Objective;
/// Returns selected solutions base on current context.
fn selected<'a>(&'a self) -> Box<dyn Iterator<Item = &Self::Solution> + 'a>;
/// Returns subset of solutions within their rank sorted according their quality.
fn ranked<'a>(&'a self) -> Box<dyn Iterator<Item = (&Self::Solution, usize)> + 'a>;
/// Returns current statistic used to track the search progress.
fn statistics(&self) -> &HeuristicStatistics;
/// Returns selection phase.
fn selection_phase(&self) -> SelectionPhase;
/// Returns environment.
fn environment(&self) -> &Environment;
/// Updates population with initial solution.
fn on_initial(&mut self, solution: Self::Solution, item_time: Timer);
/// Updates population with a new offspring.
fn on_generation(&mut self, offspring: Vec<Self::Solution>, termination_estimate: f64, generation_time: Timer);
/// Returns final population and telemetry metrics
fn on_result(self) -> HeuristicResult<Self::Objective, Self::Solution>;
}
/// A refinement statistics to track evolution progress.
#[derive(Clone)]
pub struct HeuristicStatistics {
/// A number which specifies refinement generation.
pub generation: usize,
/// Elapsed seconds since algorithm start.
pub time: Timer,
/// A current refinement speed.
pub speed: HeuristicSpeed,
/// An improvement ratio from beginning.
pub improvement_all_ratio: f64,
/// An improvement ratio over last 1000 iterations.
pub improvement_1000_ratio: f64,
/// A progress till algorithm's termination.
pub termination_estimate: f64,
}
impl Default for HeuristicStatistics {
fn default() -> Self {
Self {
generation: 0,
time: Timer::start(),
speed: HeuristicSpeed::Unknown,
improvement_all_ratio: 0.,
improvement_1000_ratio: 0.,
termination_estimate: 0.,
}
}
}
/// A default heuristic context implementation which uses telemetry to track search progression parameters.
pub struct TelemetryHeuristicContext<O, S>
where
O: HeuristicObjective<Solution = S>,
S: HeuristicSolution,
{
objective: Arc<O>,
population: Box<DynHeuristicPopulation<O, S>>,
telemetry: Telemetry<O, S>,
environment: Arc<Environment>,
}
impl<O, S> TelemetryHeuristicContext<O, S>
where
O: HeuristicObjective<Solution = S>,
S: HeuristicSolution,
{
/// Creates a new instance of `TelemetryHeuristicContext`.
pub fn new(
objective: Arc<O>,
population: Box<DynHeuristicPopulation<O, S>>,
telemetry_mode: TelemetryMode,
environment: Arc<Environment>,
) -> Self {
let telemetry = Telemetry::new(telemetry_mode);
Self { objective, population, telemetry, environment }
}
/// Adds solution to population.
pub fn add_solution(&mut self, solution: S) {
self.population.add(solution);
}
}
impl<O, S> HeuristicContext for TelemetryHeuristicContext<O, S>
where
O: HeuristicObjective<Solution = S>,
S: HeuristicSolution,
{
type Objective = O;
type Solution = S;
fn objective(&self) -> &Self::Objective {
&self.objective
}
fn selected<'a>(&'a self) -> Box<dyn Iterator<Item = &Self::Solution> + 'a> {
self.population.select()
}
fn ranked<'a>(&'a self) -> Box<dyn Iterator<Item = (&Self::Solution, usize)> + 'a> {
self.population.ranked()
}
fn statistics(&self) -> &HeuristicStatistics {
self.telemetry.get_statistics()
}
fn selection_phase(&self) -> SelectionPhase {
self.population.selection_phase()
}
fn environment(&self) -> &Environment {
self.environment.as_ref()
}
fn on_initial(&mut self, solution: Self::Solution, item_time: Timer) {
self.telemetry.on_initial(&solution, item_time);
self.population.add(solution);
}
fn on_generation(&mut self, offspring: Vec<Self::Solution>, termination_estimate: f64, generation_time: Timer) {
let is_improved = self.population.add_all(offspring);
self.telemetry.on_generation(
self.objective.as_ref(),
self.population.as_ref(),
termination_estimate,
generation_time,
is_improved,
);
self.population.on_generation(self.telemetry.get_statistics());
}
fn on_result(self) -> Result<(Box<DynHeuristicPopulation<O, S>>, Option<TelemetryMetrics>), GenericError> {
let mut telemetry = self.telemetry;
telemetry.on_result(self.objective.as_ref(), self.population.as_ref());
Ok((self.population, telemetry.take_metrics()))
}
}
/// Defines instant refinement speed type.
#[derive(Clone, Debug)]
pub enum HeuristicSpeed {
/// Not yet calculated
Unknown,
/// Slow speed.
Slow {
/// Ratio.
ratio: f64,
/// Average refinement speed in generations per second.
average: f64,
/// Median estimation of running time for each generation (in ms).
median: Option<usize>,
},
/// Moderate speed.
Moderate {
/// Average refinement speed in generations per second.
average: f64,
/// Median estimation of running time for each generation (in ms).
median: Option<usize>,
},
}
impl HeuristicSpeed {
/// Returns a median estimation of running time for each generation (in ms)
pub fn get_median(&self) -> Option<usize> {
match self {
HeuristicSpeed::Unknown => None,
HeuristicSpeed::Slow { median, .. } => *median,
HeuristicSpeed::Moderate { median, .. } => *median,
}
}
}
/// A trait which specifies object with state behavior.
pub trait Stateful {
/// A key type.
type Key: Hash + Eq;
/// Saves state using given key.
fn set_state<T: 'static + Send + Sync>(&mut self, key: Self::Key, state: T);
/// Tries to get state using given key.
fn get_state<T: 'static + Send + Sync>(&self, key: &Self::Key) -> Option<&T>;
/// Gets state as mutable, inserts if not exists.
fn state_mut<T: 'static + Send + Sync, F: Fn() -> T>(&mut self, key: Self::Key, inserter: F) -> &mut T;
}
/// Gets default population selection size.
pub fn get_default_selection_size(environment: &Environment) -> usize {
environment.parallelism.available_cpus().min(8)
}
/// Gets default population algorithm.
pub fn get_default_population<O, S>(
objective: Arc<O>,
environment: Arc<Environment>,
selection_size: usize,
) -> Box<dyn HeuristicPopulation<Objective = O, Individual = S> + Send + Sync>
where
O: HeuristicObjective<Solution = S> + Shuffled + 'static,
S: HeuristicSolution + RosomaxaWeighted + DominanceOrdered + 'static,
{
if selection_size == 1 {
Box::new(Greedy::new(objective, 1, None))
} else {
let config = RosomaxaConfig::new_with_defaults(selection_size);
let population =
Rosomaxa::new(objective, environment, config).expect("cannot create rosomaxa with default configuration");
Box::new(population)
}
}