Halton¶ ↑

A Ruby library for the fast generation of Halton sequences, a deterministic low discrepancy sequence that appears to be random. The uniform distribution and repeatability makes the sequence ideal for choosing sample points or placing objects in 2D or 3D space.

grid = 10.times.map {10.times.map {"."}}
Halton.each(2, 3).take(26).zip("A".."Z") do |(x, y), c|
  grid[y * 10][x * 10] = c
end
grid.each {|row| puts row.join(" ")}

Outputs:

. . R . . I . . . .
. L . . . . U C . .
X . . F . . . . . O
. . . J . A . . . .
. D . . . . M S . .
P . . . V . . . G .
. . B . . Y . . . .
. T . . . . E . K .
H . . . N . . . . W
. . . Z . Q . . . .

The method of generation is adapted from “Fast, portable, and reliable algorithm for the calculation of Halton numbers” by Miroslav Kolář and Seamus F. O’Shea.

Install via Rubygems:

gem install halton

or add it to your Gemfile if you’re using Bundler:

gem "halton"

and then run the bundle command to install.

This gem requires a Rust compiler and the cargo build tool to build the gem’s native extension. See www.rust-lang.org/tools/install for how to install Rust. cargo is usually part of the Rust installation.