#!/usr/bin/env ruby

require 'optparse'

options = {}

OptionParser.new do |opts|

  opts.banner = "Usage: #{$0} [OPTIONS]"

  opts.on('-m', '--min-sigma [min]', 'Min sigma.') do |value|
    options[:min_sigma] = value.gsub(/\\/, '').to_f
  end

  opts.on('-a', '--max-sigma [max]', 'Max sigma.') do |value|
    options[:max_sigma] = value.gsub(/\\/, '').to_f
  end

  opts.on('-c', '--column [max]', 'Col to be parsed.') do |value|
    options[:column] = value.to_i
  end

  opts.on('-k', '--kdev [max]', 'kdev.') do |value|
    options[:kdev] = value.to_i
  end

end.parse!

required_options = [:min_sigma, :max_sigma, :column, :kdev]
required_options.each do |option|
  unless options[option]
    $stderr.puts "Can not run #{option.to_s} was not given."
    exit 1
  end
end

class Array
  def mean
    product / size
  end

  def product
    sum
  end
  def sum_of_squares(avg = nil)
    avg = mean unless avg
    sqares = map do |number|
      result = number - avg
      result ** 2
    end
    sqares.sum
  end

  def variance(minus = 0)
    sum_of_squares / (size - minus)
  end

  def standard_deviation
    Math.sqrt(variance(1.5))
  end

  def population_standard_deviation
    Math.sqrt(variance(0))
  end

  def median
    return size[0] if size == 1
    self[(size + 1) / 2]
  end

  def sample_standard_deviation
    med = median
    sqr = map do |number|
      result = number - med
      result ** 2
    end
    Math.sqrt(sqr.mean)
  end

  def sum
    inject do |cumulative, value|
      cumulative += value
    end
  end

end

data = []

STDIN.each_line do |line|
  line.chomp!
  index = options[:column]
  item = line.split(' ')[index - 1]
  data.push({ :number => item.to_f, :line => line })
end

numbers = data.map do |object|
  object[:number]
end

options[:standard_deviation] = numbers.standard_deviation
options[:min_deviation_from_mean] = (options[:min_sigma] * options[:standard_deviation] + numbers.mean)
options[:max_deviation_from_mean] = (options[:max_sigma] * options[:standard_deviation] + numbers.mean)

data.each do |object|

  smaller_than_max = (object[:number] > options[:min_deviation_from_mean])
  bigger_than_min  = (object[:number] < options[:max_deviation_from_mean])

  # $stderr.puts [
  #   smaller_than_max,
  #   object[:number],
  #   bigger_than_min,
  #   options[:min_deviation_from_mean],
  #   options[:max_deviation_from_mean]
  # ].map { |x| x.inspect } * ' '
  

  if smaller_than_max && bigger_than_min
    puts object[:line]
  end
end

def pretty_options(hash, width = 20)
  r = ''
  hash.keys.sort.each do |key|
    k = key.to_s.ljust(width, '.')
    v = hash[key].to_s.rjust(width, '.')
    r << [k, v] * ' ' + "\n"
  end
  r
end

# $stderr.puts pretty_options(options)