From: William James <w_a_x_man@...>
Date: 2007-02-08T07:10:09+09:00
Subject: Re: histogram of histograms

On Feb 7, 2:53 pm, "Charles L. Snyder" <clsny...@gmail.com> wrote:
> Hi
>
> I have several text files that look like this:
>
> Brazil, 10
> Brazil, 13
> Brazil, 9
> Bulgaria, 1
> Canada, 48
> Canada, 52
> Canada, 38
> Canada, 55
> Canada, 59
> Chile, 1
> Chile, 1
> Chile, 2
> China, 7
> China, 18
> China, 19
> China, 22
> China, 25
>
> I need to iterate through the above file(s) and get the data
> summarized in the form:
>
> Canada, 252
> China, 91
> Chile, 4
> Brazil, 32
> Bulgaria, 1
>
> I know how to go from a single column list with multiple repeated
> values to a 'histogram' type list, ie:
>
> my_hash = countries.inject(Hash.new { 0 }) { |counts, key| counts[key]
> += 1; counts}
> my_hash = my_hash.sort { |a,b| a[1] <=> b[1] }
>
> but I'm unable to figure out how to get the 2-column csv values into a
> total by country as shown above.
> (I do have another file "countries.txt" which is a unique list of
> countries.)
>
> Thanks in advance!
>
> CLS


hash = Hash.new(0)
"\
Brazil, 10
Brazil, 13
Brazil, 9
Bulgaria, 1
Canada, 48
Canada, 52
Canada, 38
Canada, 55
Canada, 59
Chile, 1
Chile, 1
Chile, 2
China, 7
China, 18
China, 19
China, 22
China, 25".each{|s| s.split(',').inject{|k,v| hash[k] += v.to_i }}
p hash