composition.rb

#! /usr/local/bin/ruby

require 'rubygems'
require 'fastercsv'

layout = Hash.new

FasterCSV.open(ARGV.first, :headers => true).each do |row|
  row.headers.each do |header|
    layout[header] ||= Hash.new
    layout[header][row['amino_acid']] = row[header].to_i
  end
end

numbers = {'nitrogen' => 1, 'carbon' => 2, 'oxygen' => 2, 'hydrogen' => 4}

numbers.keys.each do |atom|
  layout[atom].keys.each do |acid|
    layout[atom][acid] = layout[atom][acid] + numbers[atom]
  end
end

puts YAML.dump(layout)

weight.rb

#! /usr/local/bin/ruby

require 'rubygems'

weights = { 'carbon'  => 12.011, 'nitrogen' => 14.007,
            'oxygen'  => 15.999, 'hydrogen' => 1.0079,
            'sulphur' => 32.065  }

composition = YAML.load(File.open(ARGV.first).read)

weights.keys.each do |atom|
  composition[atom].keys.each do |acid|
    composition[atom][acid] = composition[atom][acid] * weights[atom]
  end
end

puts YAML.dump(composition)