From: Robert Klemme <shortcutter@...>
Date: 2008-12-18T17:34:06+09:00
Subject: Re: Using ruby hash on array

2008/12/17 Stuart Clarke <stuart.clarke1986@gmail.com>:
> I would like to process some data from an array and using hash to
> perform a count on one aspect of the data in the array. The array holds
> lines of similarly formatted data like so
>
> data A      data B     data C     data D     data E     data F
> data A      data B     data C     data D     data E     data F
> data A      data B     data C     data D     data E     data F

You do not say whether the format is delimited or fixed width.

> data A is the identifier of each row full of data, data F contains a lot
> of data which requires a regular expression which is passed to a method
> for example:
>
> "#{data F[/Name:\t(.+?)\r\n/, 1]}"
>
> I am stuck writing the hash section of the code. The alogorithm is
>
> if data A == 100
> load data F reg expression into hash
> end
> count data F to determine the number of each name extracted by the
> regular expression
> print bob 6, sue 12, tim 1

A framework:

Data = Struct.new :a, :b:, :c, :d, :e, :f

def Data.parse(line)
  d = new(*line.strip.split(/\s+/))
  d.f = Integer(d.f)
  d
end

count = Hash.new 0

ARGF.each do |line|
  data = Data.parse(line)
  count[data.f[/Name:\t(.+?)\r\n/, 1]] += 1 if data.a == 100
end

count.each do |a, cnt|
  printf "%20s %6d\n", a, cnt
end

Kind regards

robert

-- 
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