From: Jim Freeze <jim@...>
Date: 2005-07-16T03:49:14+09:00
Subject: Re: [QUIZ] Sampling (#39)

> >    $ time ./sample 5_000_000 1_000_000_000 > big_sample.txt
> >
> >    real    30m10.593s
> >    user    29m54.544s
> >    sys     0m4.736s

Here are my results on a lowly powerbook:

  time ./sample 5_000_000 1_000_000_000 > /dev/null
  136.990u 1.120s 2:50.91 80.8%   0+0k 0+0io 0pf+0w

  time ./sample 5_000_000 1_000_000_000 > big_sample.txt
  222.100u 2.500s 3:53.70 96.1%   0+0k 1+28io 0pf+0w

  % head big_sample.txt 
  402
  421
  549
  571
  757
  1025
  1224
  1604
  2064
  2602
  % tail big_sample.txt 
  999998571
  999998613
  999998644
  999998648
  999998841
  999999116
  999999414
  999999609
  999999609
  999999915

Here's my typical interaction with a program.
(I usually seem to be able to find all the ways
that don't work first.)
I've included a source listing of the application
part of the code to demonstrate commandline.

  % ./sample 
   Usage: sample [-h] number limit

  % ./sample -h
  NAME

      sample - Generate a list of samples

  SYNOPSIS

      sample [-h] number limit

  OPTIONS

      --help,-h
          Displays help page.

  % ./sample 10 9
  ERROR: Number must be less than or equal to limit.

  % ./sample 10 11.1
  ERROR: Argument 'limit' with value '11.1' must be an integer.
   Usage: sample [-h] number limit

  % ./sample 10.1 11
  ERROR: Argument 'number' with value '10.1' must be an integer.
   Usage: sample [-h] number limit

  % ./sample 3 10
  3
  4

  % ./sample 5 20
  6
  7
  9
  14
  18


  % cat sample
  #!/usr/bin/env ruby

  begin
    require 'commandline'
  rescue LoadError
    require 'rubygems'
    retry
  end

  class App < CommandLine::Application

    def initialize
      synopsis          "[-h] number limit"
      short_description "Generate a list of samples"
      option :help
      expected_args :number, :limit
    end

    def convert_to_integer(*args)
      arg, val = nil, nil
      args.each { |arg|
        val = instance_variable_get("@#{arg}")
        instance_variable_set("@#{arg}", Integer(val))
      }
      rescue
        raise "Argument '#{arg}' with value '#{val}' must be an integer.\n"+
              usage
    end

    def main
      convert_to_integer :number, :limit

      puts Sample.create_sample_list(@number, @limit)
    end

  end#class App


  class Sample
    def self.create_sample_list(number, limit)
      Sample.new(number, limit).samples
    end
    #.... no peeking...
    #.... sorry, you won't find a spoiler here...
-- 
Jim Freeze