alps.h File Reference

#include "kernel/population.h"
#include <array>
#include <cstddef>
#include <functional>
#include <span>

Go to the source code of this file.

Classes
class	ultra::alps_layer_pair< Layer >
struct	ultra::alps::parameters

Namespaces
namespace	ultra

Functions
template<class Layer>
	ultra::alps_layer_pair (Layer &) -> alps_layer_pair< Layer >
template<class Layer>
	ultra::alps_layer_pair (Layer &, Layer &) -> alps_layer_pair< Layer >
template<class Layer>
	ultra::alps_layer_pair (const Layer &) -> alps_layer_pair< const Layer >
template<class Layer>
	ultra::alps_layer_pair (const Layer &, const Layer &) -> alps_layer_pair< const Layer >
template<LayeredPopulation P>
void	ultra::alps::set_age (P &pop)
template<LayeredPopulation P>
alps_layer_pair< typename P::layer_t >	ultra::alps::replacement_layers (P &pop, typename P::layer_iter l)
template<LayeredPopulation P>
alps_layer_pair< const typename P::layer_t >	ultra::alps::selection_layers (const P &pop, typename P::layer_const_iter l)

Detailed Description

Remarks

This file is part of ULTRA.

Copyright

Copyright (C) 2024 EOS di Manlio Morini.

License

This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0. If a copy of the MPL was not distributed with this file, You can obtain one at http://mozilla.org/MPL/2.0/

Function Documentation

replacement_layers()

template<LayeredPopulation P>

alps_layer_pair< typename P::layer_t > ultra::alps::replacement_layers	(	P &	pop,
		typename P::layer_iter	l )

Determines the set of layers whose individuals may be replaced by offspring generated from the specified layer.

Parameters

[in]	pop	layered population
[in]	l	iterator to the layer producing the offspring

Returns

an alps_layer_pair containing the layers eligible for replacement

Precondition

pop contains at least one layer

l is a valid iterator into pop.range_of_layers()

In the ALPS paradigm, replacement is restricted in order to preserve age stratification. Individuals are typically replaced either within the same layer or, in some cases, in the oldest layer.

The replacement policy implemented here is:

• if l refers to the last (oldest) layer, only that layer is eligible;
• otherwise, both the current layer and the last layer are eligible.

Note

The returned object stores references to layers owned by pop; it doesn't extend their lifetime.

selection_layers()

template<LayeredPopulation P>

alps_layer_pair< const typename P::layer_t > ultra::alps::selection_layers	(	const P &	pop,
		typename P::layer_const_iter	l )

Determines the set of layers from which parents may be selected when generating offspring for the specified layer.

Parameters

[in]	pop	layered population
[in]	l	iterator to the layer for which parents are being selected

Returns

an alps_layer_pair containing the layers eligible for parent selection

Precondition

pop contains at least one layer

l is a valid iterator into pop.range_of_layers()

In ALPS, parent selection is typically restricted to the same age layer or younger ones, preventing older individuals from influencing younger layers.

The selection policy implemented here is:

• if l refers to the first (youngest) layer, only that layer is used;
• otherwise, both the current layer and the immediately younger layer are used.

Note

The returned object stores references to layers owned by pop; it doesn't extend their lifetime.