From: Jack Bauer <realmadrid2727@...>
Date: 2009-04-30T23:23:28+09:00
Subject: Re: Advanced array merging

7stud -- wrote:
> 
> Those two requirements are often at odds with each other.  For instance, 
> "inject" and "fastest" should not be used in the same sentence.
> 
> result = []
> 
> arr.each do |sub_arr|
>   counter_total = 0
> 
>   sub_arr.each do |obj|
>     counter_total += obj.counter
>   end
> 
>   sub_arr[0].counter = counter_total
>   result << sub_arr[0]   #or result << [sub_arr[0]]
> end


Thanks, 7stud. I forgot to mention in my description that after it did 
the sum of the first item in each of the 3 subarrays to move on and do 
all the second items, then the third, etc. Using yours as a base I ended 
up with:

index = 0
array[0].length.times do
  counter_total = 0
  array.each do |sub_array|
    counter_total += sub_array[index].counter
  end
  array[0][index].counter = counter_total
  data_stream_out << array[0][index]
  index += 1
end

Works like a charm and enormously faster than what I was doing before I 
posted this thread. Before I asked for help here I was using inject and 
the calculation was taking 28 seconds to complete. This one took 4 and 
there were about 2,000 more records this time too.
-- 
Posted via http://www.ruby-forum.com/.