`differential_evolution_problem_protocol`

Protocol for continuous bounded Differential Evolution problem definitions.

| Availability: | logtalk_load(differential_evolution(loader))

| Author: Paulo Moura | Version: 1:0:0 | Date: 2026-08-13

| Compilation flags: | static

| Dependencies: | (none)

| Remarks: | (none)

| Inherited public predicates: | (none)

.. contents:: :local: :backlinks: top

Public predicates

.. index:: position_bounds/1 .. _differential_evolution_problem_protocol/0::position_bounds/1:

position_bounds/1 ^^^^^^^^^^^^^^^^^^^^^

Returns one Lower-Upper numeric bound pair per dimension, with Lower =< Upper.

| Compilation flags: | static

| Template: | position_bounds(Bounds) | Mode and number of proofs: | position_bounds(-list(pair)) - one

.. index:: fitness/2 .. _differential_evolution_problem_protocol/0::fitness/2:

fitness/2 ^^^^^^^^^^^^^

Computes the fitness of a candidate solution. The optimization direction is selected by the objective/1 option.

| Compilation flags: | static

| Template: | fitness(Position,Fitness) | Mode and number of proofs: | fitness(+list(number),-number) - one

.. index:: initial_positions/1 .. _differential_evolution_problem_protocol/0::initial_positions/1:

initial_positions/1 ^^^^^^^^^^^^^^^^^^^^^^^

Optional. Returns a non-empty list of initial positions. When not defined, the algorithm generates a random initial population inside the position bounds.

| Compilation flags: | static

| Template: | initial_positions(Positions) | Mode and number of proofs: | initial_positions(-list(list(number))) - zero_or_one

.. index:: stop_condition/3 .. _differential_evolution_problem_protocol/0::stop_condition/3:

stop_condition/3 ^^^^^^^^^^^^^^^^^^^^

Optional. True when the search should stop given the completed generation, best position, and best fitness.

| Compilation flags: | static

| Template: | stop_condition(Generation,BestPosition,BestFitness) | Mode and number of proofs: | stop_condition(+non_negative_integer,+list(number),+number) - zero_or_one

.. index:: progress/5 .. _differential_evolution_problem_protocol/0::progress/5:

progress/5 ^^^^^^^^^^^^^^

Optional. Called periodically with generation, best position, best fitness, mean population fitness, and population diversity (mean Euclidean distance from the centroid).

| Compilation flags: | static

| Template: | progress(Generation,BestPosition,BestFitness,MeanFitness,Diversity) | Mode and number of proofs: | progress(+non_negative_integer,+list(number),+number,+number,+number) - zero_or_one

Protected predicates

(none)

Private predicates

(none)

Operators

(none)

.. seealso::

:ref:`differential_evolution(Problem) <differential_evolution/1>`, :ref:`differential_evolution(Problem,RandomAlgorithm) <differential_evolution/2>`