Class: FeldtRuby::Optimize::Optimizer

Inherits:
Object
  • Object
show all
Includes:
Logging
Defined in:
lib/feldtruby/optimize/optimizer.rb

Overview

Find an vector of float values that optimizes a given objective.

Direct Known Subclasses

PopulationBasedOptimizer, RandomSearcher

Instance Attribute Summary collapse

Attributes included from Logging

#logger

Instance Method Summary collapse

Methods included from Logging

#__find_logger_set_on_instance_vars, #new_default_logger, #setup_logger_and_distribute_to_instance_variables

Constructor Details

#initialize(objective, searchSpace = FeldtRuby::Optimize::DefaultSearchSpace, options = {}) ⇒ Optimizer

Returns a new instance of Optimizer.



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# File 'lib/feldtruby/optimize/optimizer.rb', line 20

def initialize(objective, searchSpace = FeldtRuby::Optimize::DefaultSearchSpace, options = {})
	@objective, @search_space = objective, searchSpace
	@options = FeldtRuby::Optimize.override_default_options_with(options)

	init_archive

	# Must setup logger before setting options since verbosity of logger is
	# an option!
	setup_logger_and_distribute_to_instance_variables(options)

	initialize_options(@options)
end

Instance Attribute Details

#archive ⇒ Object (readonly)

Returns the value of attribute archive.



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# File 'lib/feldtruby/optimize/optimizer.rb', line 17

def archive
  @archive
end

#num_optimization_steps ⇒ Object (readonly)

Returns the value of attribute num_optimization_steps.



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# File 'lib/feldtruby/optimize/optimizer.rb', line 18

def num_optimization_steps
  @num_optimization_steps
end

#objective ⇒ Object (readonly)

Returns the value of attribute objective.



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# File 'lib/feldtruby/optimize/optimizer.rb', line 17

def objective
  @objective
end

#options ⇒ Object (readonly)

Returns the value of attribute options.



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# File 'lib/feldtruby/optimize/optimizer.rb', line 17

def options
  @options
end

#search_space ⇒ Object (readonly)

Returns the value of attribute search_space.



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# File 'lib/feldtruby/optimize/optimizer.rb', line 17

def search_space
  @search_space
end

#termination_criterion ⇒ Object (readonly)

Returns the value of attribute termination_criterion.



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# File 'lib/feldtruby/optimize/optimizer.rb', line 18

def termination_criterion
  @termination_criterion
end

Instance Method Details

#best ⇒ Object 



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# File 'lib/feldtruby/optimize/optimizer.rb', line 51

def best
	@archive.best
end

#init_archive ⇒ Object 



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# File 'lib/feldtruby/optimize/optimizer.rb', line 33

def init_archive
	if @options[:archive]

		@archive = @options[:archive]

	else

		if @options[:archiveDiversityObjective]
			diversity_objective = @options[:archiveDiversityObjective]
		else
			diversity_objective = @options[:archiveDiversityObjectiveClass].new
		end
	
		@archive = @options[:archiveClass].new(@objective, diversity_objective)

	end
end

#initialize_options(options) ⇒ Object 



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# File 'lib/feldtruby/optimize/optimizer.rb', line 55

def initialize_options(options)
	self.logger.verbose = options[:verbose]
	@termination_criterion = options[:terminationCriterion]
end

#log_end_of_optimization ⇒ Object 



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# File 'lib/feldtruby/optimize/optimizer.rb', line 90

def log_end_of_optimization
	logger.log("End of optimization\n" + 
		"  Optimizer: #{self.class}\n" +
		"  Best found: #{@archive.best}\n" +
		"  Quality of best: #{@objective.quality_of(@archive.best)}\n" +
		"  Time used = #{Time.human_readable_timestr(logger.elapsed_time)}, " + 
		  "Steps performed = #{@num_optimization_steps}, " + 
		  "#{Time.human_readable_timestr(time_per_step, true)}/step")
end

#optimization_step ⇒ Object

Run one optimization step. Default is to do nothing, i.e. this is just a superclass, but subclasses need to implement this.



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# File 'lib/feldtruby/optimize/optimizer.rb', line 106

def optimization_step()
end

#optimize ⇒ Object

Optimize the objective in the given search space.



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# File 'lib/feldtruby/optimize/optimizer.rb', line 61

def optimize()
	logger.log "Optimization with optimizer #{self.class.inspect} started"
	@num_optimization_steps = 0

	# Set up a random best for now that we can later compare to.
	update_archive [search_space.gen_candidate()]

	begin
		while !termination_criterion.terminate?(self)
			new_candidates = optimization_step()
			@num_optimization_steps += 1
			update_archive new_candidates
		end
	rescue Exception => e
		puts e.inspect
		logger.log_data :exception, {
			:exception_class => e.class.inspect, 
			:backtrace => e.backtrace.join("\n")
		}, "!!! - Optimization FAILED with exception: #{e.message} - !!!" + e.backtrace.join("\n")
	ensure
		logger.log "!!! - Optimization FINISHED after #{@num_optimization_steps} steps - !!!"
	end

	@objective.note_end_of_optimization(self)
	log_end_of_optimization

	archive.best # return the best
end

#time_per_step ⇒ Object 



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# File 'lib/feldtruby/optimize/optimizer.rb', line 100

def time_per_step
	logger.elapsed_time / @num_optimization_steps
end

#update_archive(candidates) ⇒ Object

Update the archive with newly found candidates. Array of candidates may be empty if no new candidates found.



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# File 'lib/feldtruby/optimize/optimizer.rb', line 111

def update_archive(candidates)
	candidates.each {|c| @archive.add(c)}
end