cartesian

DESCRIPTION:

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.

FEATURES:

The module is automatically mixed in Array class, but the names of the methods for mixin are different.

Module:

Cartesian::product(foo, bar)

Mixin:

foo.cartesian( bar )

SYNOPSIS:

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]]
for x, y, z in 0..1

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

u = [0,1]**3 #=> #<CartesianIterator:0x7f2fb8e54978 @tot_iter=8, @lists=[[0, 1], [0, 1], [0, 1]]>
u.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]]

v = []
for x, y, z in (0...10)**3
  v << [x, y, z] if x*x + y*y + z*z == 6
end
v #=> [[1, 1, 2], [1, 2, 1], [2, 1, 1]]

Finally, the grid search methods

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

REQUIREMENTS:

  • None, besides the Ruby interpreter and standard library. This gems was successfully tested on all relevant Ruby versions: MRI/YARV, JRuby, Rubinius, and REE. For details, see History.txt.

INSTALL:

  • sudo gem install cartesian

LICENSE:

(The MIT License)

Copyright © 2006-2012 Adriano Mitre <[email protected]>

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the ‘Software’), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED ‘AS IS’, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.