h1. cartesian h3. Cartesian products in Ruby h2. What Provides methods for the calculation of the cartesian producted between two or more enumerable objects. Includes grid search optimization methods. It can also be easily and conveniently mixed-in into any enumerable class. h2. Installing

sudo gem install cartesian

h2. The basics

Cartesian::product [1,2],[3,4] #=> [[1, 3], [1, 4], [2, 3], [2, 4]]

h2. Demonstration of usage One can use the Cartesian module directly

require 'cartesian'
foo = [1, 2]
bar = ["a", "b"]
Cartesian::product(foo, bar) #=> [[1, "a"], [1, "b"], [2, "a"], [2, "b"]]

or use the methods provided by the mixin in the Array class

foo.cartesian(bar)  #=> [[1, "a"], [1, "b"], [2, "a"], [2, "b"]]

which include the short'n'sweet _x_ method

v = [] #=> []
for a,b in [1,2].x [3,4]
  v << [a,b]
end #=> true
v #=> [[1, 3], [1, 4], [2, 3], [2, 4]]

The '**' operator provides a convenient way of iterating multi-dimensionally over the same array or range

v = [0,1]**3 #=> #
v.to_a #=> [[0, 0, 0], [0, 0, 1], [0, 1, 0], [0, 1, 1], [1, 0, 0], [1, 0, 1], [1, 1, 0], [1, 1, 1]]

Finally, the grid search methods

require 'grid_search'
[-1, 0, 1, 2].argmax {|x| x**2 } #=> 2
[-1, 0, 1, 2].argmin {|x| x.abs } #=> 0

For more examples and details, see the RDoc-generated documentation "here":doc/index.html. h2. How to submit patches Read the "8 steps for fixing other people's code":http://drnicwilliams.com/2007/06/01/8-steps-for-fixing-other-peoples-code/ and for section "8b: Submit patch to Google Groups":http://drnicwilliams.com/2007/06/01/8-steps-for-fixing-other-peoples-code/#8b-google-groups, use the Google Group above. You can fetch the source from: * github: "http://github.com/adrianomitre/cartesian/tree/master":http://github.com/adrianomitre/cartesian/tree/master

git clone git@github.com:adrianomitre/cartesian.git

h3. Build and test instructions

cd cartesian
rake test
rake install_gem

h2. License This code is free to use under the terms of the MIT license. h2. Contact Comments are welcome. Send an email to "Adriano Mitre":mailto:adriano.mitre@gmail.com.