Could someone please add comments to this code? Or, alternatively, what would be the pseudocode equivalent of this Ruby code?

It seems simple enough but I just don't know enough Ruby to convert this to PHP.

data = Hash.new({})
mysql_results.each { |r| data[r['year']][r['week']] = r['count'] }

(year_low..year_high).each do |year|
  (1..52).each do |week|
   puts "#{year} #{week} #{data[year][week]}"
  end
end

Any help whatsoever would be really appreciated.

Thanks!