m9t

Measurements and coversions library for Ruby

• Source Code
• API documentation
• Rubygem
• Continuous Integration

This package handles the basic units of measure:

• distance,
• direction,
• speed,
• temperature,
• weight.

The emphasis is on:

• coherent interface,
• ease of translation (using i18n).

Internals

Internally, values are stored in SI units, with the exception of temperature:

• distance - meters,
• direction - degrees,
• speed - meters per second,
• temperature - degrees celcius,
• weight - kilograms.

Interface

new: accepts the S.I. unit as a parameter:

height = M9t::Distance.new(1.75)

to_f: returns the decimal value(s):

height.to_f -> 1.75

other units: there are class methods named after each known unit, which take values in that unit (actually, they are defined as needed):

marathon = M9t::Distance.miles(26.21875)
marathon.to_f -> 42194.988

to_s: returns a localized string with units:

I18n.locale = :it
puts M9t::Distance.new(3).to_s -> '3 metri'

Class methods for conversion

Methods are available for conversion between any pair of units:

M9t::Distance.miles_to_meters(26.21875) -> 42194.988

Testing

Coverage

ruby 1.8.x:

$ rake rcov

ruby 1.9.x:

$ COVERAGE=1 rake test

Alternatives

• ruby-units
  • Doesn't handle i18n:
    • The library depends heavily on English string representations of units.
  • Monkey patches a lot of core classes:
    • Adds methods to e.g. Object.

License

Dual license:

• MIT License: see MIT-LICENSE.txt,
• GPL version 3: see GPL-LICENSE.txt