From: Guillaume Marcais <guslist@...>
Date: 2005-09-07T08:42:17+09:00
Subject: Re: [ANN] Units for Ruby

On Wed, 2005-09-07 at 07:46 +0900, Lucas Carlson wrote:
> I have also created a new library to add units to numbers in Ruby:
> 
> gem install units
> http://units.rubyforge.org/
> 
> It is extremely simple to use:
> 
>     require 'units/standard'
>     1.lb.to_ounces # => 16.0
> 
>     require 'units/currency'
>     1.euro.usd # => 1.2545
> 
>     1.usd.unit # => :usd
>     1.usd.to_yen # => 108.9 # this information is grabbed on the fly
> via a SOAP call
>     1.usd.to_yet.unit # => :yen
> 
> It is also very simple to add both static and dynamic conversions on
> your own via add_unit_conversions and add_unit_aliases.
> 
> I hope you find this library useful too.
> 

Looking good.

Some volume conversion seems to be wrong thought:

irb(main):007:0> 1.teaspoons.to_cubic_meters ** (1.0 / 3)
=> 58.7601229917626

That's a very deep Olympic size swimming pool!


Trusting google for unit conversion:

[gus@comp tmp]$ ruby get_standard.rb 2>/dev/null
:pints                => 0.125,
:milliliters          => 0.000264172051,
:cubic_feet           => 7.48051945,
:cups                 => 0.0625,
:microliters          => 2.64172051,
:cubic_inches         => 0.00432900431,
:liters               => 0.264172051,
:cubic_centimeters    => 0.000264172051,
:cubic_yards          => 201.974025,
:hectoliters          => 26.4172051,
:fluid_ounces         => 0.0078125,
:cubic_millimeters    => 2.64172051,
:gallons              => 1,
:deciliters           => 0.0264172051,
:tablespoons          => 0.00390625,
:cubic_meters         => 264.172051,
:quarts               => 0.25,
:centiliters          => 0.00264172051,
:teaspoons            => 0.00130208333,
:cubic_decimeters     => 0.264172051,

[gus@comp tmp]$ cat get_standard.rb
require 'units/standard'
require 'net/http'

h = Net::HTTP.new('www.google.com', 80)
Numeric::VOLUME.keys.each do |u|
  v = u.to_s.gsub(/_/, " ")
  resp, data = h.get("/search?q=1+#{v.gsub(/ /, "+")}+in+gallon", nil)
  if data =~ /\(?#{v}\)?\s*=\s*([\d.]+)/
      val = $1
      puts(":%-20s => #{val}," % u)
  else
    $stderr.puts("#{u} failed")
  end
end

Thank you for your library,
Guillaume.