#!/usr/bin/env ruby

# method definition
def create_array(data) # change to whatever
  data.chomp.split(' ').map(&:to_i) # returns array of ints
end

def calc_average(data) # change to whatever
  data.inject(0, :+).fdiv(2) # returns a float
end

def calc_standard_deviation(data) # change to whatever
  Math.sqrt(data.map {|n| n**2}.inject(0, :+).fdiv(data.size)) #return a float
end

def calc_median(data) # change to whatever
  data.sort! # sort the array in ascending order
  (data[data.size-1]).fdiv(2) + data[data.size.fdiv(2)].fdiv(2) # return a float
end

unless ARGV.size == 2
  STDERR.puts "Error: Incorrect number of arguements\n\nOK. Goodbye."
else
  # set command line argument1 and argument2 to in_file and out_file respectivley
  in_file = File.new(ARGV[0], 'r')
  store = in_file.each_line do |line|
    array_of_ints = create_array(line)
    average = calc_average(array_of_ints)
    s_deviation = calc_standard_deviation(array_of_ints)
    median = calc_median(array_of_ints)
  end
end