gistfile1.txt

#!/usr/bin/ruby
##Assignment 3
###Justin Beitz

def create_array(data) 
  data.chomp.split(' ').map(&:to_i)
end
 
def calc_average(data) 
  data = (data.reduce(:+) / data.size.to_f).round(4)
end
 
def calc_standard_deviation(data)
  average = data.reduce(:+) / data.size.to_f
  sum = data.inject(0){|accum, i| accum +(i-average)**2 }
  s_deviation = sum/(data.length - 1).to_f
  s_deviation = Math.sqrt(s_deviation).round(4)
end
 
def calc_median(data)
    return nil if data.empty? 
    data.sort! 
    mid = (data.length-1) / 2.0
    (data[mid.floor] + data[mid.ceil]).fdiv(2)
end  
 
def create_writefile(file, average, sd, median, data)
  File.open(ARGV[1], 'a') do |file|
    file.write("%-10s %-25s %-15s %-16s\n" % [average, sd, median, data])
  end
end
 
unless ARGV.size == 2
  STDERR.puts "Error: Incorrect number of arguements\n\nOK. Goodbye."
else
  puts "Processing: #{ARGV[0]} (input), #{ARGV[1]} (output)"
  create_writefile(ARGV[1], "Average", "Standard Deviation", "Median", "Data\n")
  in_file = File.new(ARGV[0], 'r')
  in_file.each_line.with_index do |line, idx|
    data = create_array(line)
    average = calc_average(data)
    s_deviation = calc_standard_deviation(data)
    median = calc_median(data)
    puts "Row #{idx+1}: Completed"
    create_writefile(ARGV[1], average, s_deviation, median, data)
  end
  in_file.close
  puts "\nProcess: Complete"
end