From: James Edward Gray II <james@...>
Date: 2006-12-16T09:44:08+09:00
Subject: Re: matching lines....

On Dec 15, 2006, at 6:12 PM, Just Maz wrote:

> I've got a file with a few lines:
> 1: Kevin 25 football cricket guitar
> 2: John 15 football karate
> 3: Fred 20 rugby painting
>
> Via regular expressions I'm trying to do a few things here such as
> counting how many hobbies people have and counting how many people  
> have
> the same hobby- its this last one in particular I can't figure out.

See if this gives you some fresh ideas:

persons_hobbies = Hash.new
hobbies         = Hash.new

DATA.each do |line|
   fields = line.split
   fields[3..-1].each do |hobby|
     (persons_hobbies[fields[1]] ||= Array.new) << hobby
     (hobbies[hobby] ||= Array.new) << fields[1]
   end
end

puts "=== Hobby Counts ==="
puts hobbies.map { |h, c| "#{h}: #{c.size}" }
puts "=== Personal Counts ==="
puts persons_hobbies.map { |n, c| "#{n}: #{c.size}" }

__END__
1: Kevin 25 football cricket guitar
2: John 15 football karate
3: Fred 20 rugby painting

Hope that helps.

James Edward Gray II