/// <summary>
/// Creates the collection of <see cref="GeneticEntity"/> objects contained by this population.
/// </summary>
/// <remarks>
/// <para>The default implementation of this method creates X <see cref="GeneticEntity"/> objects
/// where X is equal to <see cref="MinimumPopulationSize"/>.</para>
/// <para><b>Notes to implementers:</b> This method can be overriden in a derived class
/// to customize how a population is filled with <see cref="GeneticEntity"/> objects
/// or how those <see cref="GeneticEntity"/> objects are created.</para>
/// </remarks>
protected virtual Task InitializeCoreAsync()
{
this.AssertIsInitialized();
for (int i = 0; i < this.Algorithm !.PopulationSeed !.MinimumPopulationSize; i++)
{
GeneticEntity entity = (GeneticEntity)this.Algorithm.GeneticEntitySeed !.CreateNewAndInitialize();
this.geneticEntities.Add(entity);
}
return(Task.FromResult(true));
}
/// <summary>
/// Attempts to mutate the <paramref name="entity"/>.
/// </summary>
/// <param name="entity"><see cref="GeneticEntity"/> to be mutated.</param>
/// <returns>
/// A potentially mutated clone of the <paramref name="entity"/>.
/// </returns>
/// <remarks>
/// If the <see cref="GeneticEntity"/> was mutated, its <see cref="GeneticEntity.Age"/> property will be set to zero.
/// </remarks>
/// <exception cref="ArgumentNullException"><paramref name="entity"/> is null.</exception>
public GeneticEntity Mutate(GeneticEntity entity)
{
if (entity is null)
{
throw new ArgumentNullException(nameof(entity));
}
GeneticEntity clonedEntity = entity.Clone();
bool isMutated = this.GenerateMutation(clonedEntity);
if (isMutated)
{
clonedEntity.Age = 0;
}
return(clonedEntity);
}
/// <summary>
/// Applies the <see cref="GenFx.MutationOperator"/>, if one is set, to the <paramref name="entities"/>.
/// </summary>
/// <param name="entities">List of entities to be potentially mutated.</param>
/// <returns>List of entities after the mutation was applied.</returns>
/// <exception cref="ArgumentNullException"><paramref name="entities"/> is null.</exception>
protected IList <GeneticEntity> ApplyMutation(IList <GeneticEntity> entities)
{
if (entities == null)
{
throw new ArgumentNullException(nameof(entities));
}
if (this.MutationOperator == null)
{
return(entities);
}
List <GeneticEntity> mutants = new List <GeneticEntity>();
foreach (GeneticEntity entity in entities)
{
GeneticEntity newEntity = this.MutationOperator.Mutate(entity);
mutants.Add(newEntity);
}
return(mutants);
}
/// <summary> /// When overriden in a derived class, attempts to mutate the <paramref name="entity"/>. /// </summary> /// <param name="entity"><see cref="GeneticEntity"/> to be mutated.</param> /// <returns>true if a mutation occurred; otherwise, false.</returns> /// <remarks> /// <b>Notes to implementers:</b> When this method is overriden, each segment of data making up the /// representation of the <see cref="GeneticEntity"/> should be attempted to be mutated. Use the /// <see cref="MutationRate"/> property to determine whether a component /// of the <see cref="GeneticEntity"/> should be mutated or not. /// </remarks> protected abstract bool GenerateMutation(GeneticEntity entity);
/// <summary> /// When overriden in a derived class, returns the calculated fitness value of the <paramref name="entity"/>. /// </summary> /// <param name="entity"><see cref="GeneticEntity"/> whose calculated fitness value is to be returned.</param> /// <returns> /// The calculated fitness value of the <paramref name="entity"/>. /// </returns> public abstract Task <double> EvaluateFitnessAsync(GeneticEntity entity);