Module: Dither::IPOGHelper

Included in:
IPOG, MIPOG
Defined in:
lib/dither/ipog_helper.rb

Instance Method Summary collapse

Instance Method Details

#init_params(user_params, previously_tested) ⇒ Object 



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# File 'lib/dither/ipog_helper.rb', line 24

def init_params(user_params, previously_tested)
  tmp = []
  @input_params = user_params
  user_params.each_with_index { |e, i| tmp << [i, e] }
  @orig_params = tmp.sort_by { |a| a[1].length }
                 .reverse!

  orig_param_map = {}
  @map_to_orig_index = {}
  @orig_params.each_with_index do |e, i|
    @map_to_orig_index[i] = e[0]
    orig_param_map[e[0]] = {}
  end

  @params = []
  @unbound_param_pool = []
  orig_params.each_with_index do |e, i|
    @params << (0...e[1].length).map do |j|
      local_param = Param.new(i, j)
      orig_param_map[e[0]][e[1][j]] = local_param
      local_param
    end
    @unbound_param_pool << UnboundParam.new(i)
  end

  @tested = []
  previously_tested.each do |a|
    local_params = []
    a.each_with_index do |e, i|
      local_params << orig_param_map[i][e]
    end
    @tested << TestCase.create(params, unbound_param_pool, local_params)
  end

  params
end

#initialize(params, opts = {}) ⇒ Object

Raises:



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# File 'lib/dither/ipog_helper.rb', line 8

def initialize(params, opts = {})
  init_params(params, (opts[:previously_tested] || []))
  @t = opts[:t]
  unless opts[:constraints].nil?
    @constraints = opts[:constraints].map(&:to_a)
                   .map { |a| a.map { |b| @params[@map_to_orig_index.key(b[0])][b[1]] } }
                   .map(&:to_set)
  end

  raise Dither::Error, 't must be >= 2' if opts[:t] < 2
  raise Dither::Error, 't must be <= params.length' if opts[:t] > params.length
  params.each do |param|
    raise Dither::Error, 'param length must be > 1' if param.length < 2
  end
end

#maximize_coverage(i, test_case, pi) ⇒ Object

return nil if unable to satisfy constraints



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# File 'lib/dither/ipog_helper.rb', line 62

def maximize_coverage(i, test_case, pi)
  current_max = 0
  current_max_j = 0
  current_matches = []

  (0...params[i].length).each do |j|
    current_param = params[i][j]
    test_case << current_param
    unless violates_constraints?(test_case)
      matches = pi.select { |a| a.subset?(test_case) }
      count = matches.count

      if count > current_max
        current_max = count
        current_max_j = j
        current_matches = matches
      end
    end
    test_case.delete(current_param)
  end

  return nil if violates_constraints?(test_case)
  test_case << params[i][current_max_j]

  current_matches
end

#violates_constraints?(params) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/dither/ipog_helper.rb', line 89

def violates_constraints?(params)
  return false if constraints.nil?
  constraints.any? { |b| b.subset?(params) }
end