Class: FeldtRuby::Optimize::PopulationBasedOptimizer

Inherits:
Optimizer show all
Defined in:
lib/feldtruby/optimize/optimizer.rb

Direct Known Subclasses

EvolutionaryOptimizer

Instance Attribute Summary collapse

Attributes inherited from Optimizer

#best, #best_quality_value, #best_sub_quality_values, #num_optimization_steps, #objective, #options, #search_space, #termination_criterion

Attributes included from Logging

#logger

Instance Method Summary collapse

Methods inherited from Optimizer

#initialize, #log_end_of_optimization, #optimization_step, #optimize, #time_per_step, #update_best

Methods included from Logging

#__find_logger_set_on_instance_vars, #new_default_logger, #setup_logger_and_distribute_to_instance_variables

Constructor Details

This class inherits a constructor from FeldtRuby::Optimize::Optimizer

Instance Attribute Details

#population ⇒ Object (readonly)

Returns the value of attribute population.



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# File 'lib/feldtruby/optimize/optimizer.rb', line 154

def population
  @population
end

Instance Method Details

#get_candidate(index) ⇒ Object

Get candidate from population at given index.



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# File 'lib/feldtruby/optimize/optimizer.rb', line 199

def get_candidate(index)
	@population[index]
end

#get_candidates_with_indices(indices) ⇒ Object

Get candidates from population at given indices.



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# File 'lib/feldtruby/optimize/optimizer.rb', line 194

def get_candidates_with_indices(indices)
	indices.map {|i| @population[i]}
end

#initialize_options(options) ⇒ Object 



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# File 'lib/feldtruby/optimize/optimizer.rb', line 156

def initialize_options(options)
	super
	@population_size = @options[:populationSize]
	initialize_population(@population_size)
	@sampler = options[:samplerClass].new(self, options)
end

#initialize_population(sizeOfPopulation) ⇒ Object

Create a population of a given size by randomly sampling candidates from the search space.



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# File 'lib/feldtruby/optimize/optimizer.rb', line 164

def initialize_population(sizeOfPopulation)
	@population = Array.new(sizeOfPopulation).map {search_space.gen_candidate()}
end

#population_size ⇒ Object 



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# File 'lib/feldtruby/optimize/optimizer.rb', line 184

def population_size
	@population_size
end

#re_initialize_population(percentageOfPopulation = 0.50) ⇒ Object

Re-initialize parts of the population.



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# File 'lib/feldtruby/optimize/optimizer.rb', line 169

def re_initialize_population(percentageOfPopulation = 0.50)
	if percentageOfPopulation >= 1.00
		initialize_population(@population_size)
	else
		num_to_replace = (percentageOfPopulation * @population_size).to_i
		# We must use a PopulationSampler here instead of just calling sample_population_indices_without_replacement
		# since we do not know which sampler is installed.
		sampler = PopulationSampler.new(self, self.options)
		indices = sampler.sample_population_indices_without_replacement(num_to_replace)
		indices.each do |i|
			@population[i] = search_space.gen_candidate()
		end
	end
end

#sample_population_indices_without_replacement(numSamples) ⇒ Object

Sample indices from the population without replacement.



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# File 'lib/feldtruby/optimize/optimizer.rb', line 189

def sample_population_indices_without_replacement(numSamples)
	@sampler.sample_population_indices_without_replacement(numSamples)
end

#update_candidate_in_population(index, candidate) ⇒ Object

Update population with candidate at given index.



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# File 'lib/feldtruby/optimize/optimizer.rb', line 204

def update_candidate_in_population(index, candidate)
	@population[index] = candidate
end