Make SVG with builder

svg_builder.rb

# encoding: utf-8

require 'rubygems'
require 'builder'

svg_doctype = [
  :DOCTYPE,
  :svg,
  :PUBLIC,
  "-//W3C//DTD SVG 1.1//EN",
  "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd"
]

svg_options = {
  :xmlns         => "http://www.w3.org/2000/svg",
  :"xmlns:xlink" => "http://www.w3.org/1999/xlink",
  :"xmlns:ev"    => "http://www.w3.org/2001/xml-events",
  :version       => "1.1",
  :baseProfile   => "full",
  :width         => "1000px",
  :height        => "1000px"
}

output = String.new
svg = Builder::XmlMarkup.new indent: 2, target: output
svg.instruct!
svg.declare! *svg_doctype

svg.svg(svg_options) do
  svg.circle cx: 500, cy: 500, r: 200, style: "fill:red; stroke:black; stroke-width:10"
end

File.open('output.svg', 'w') { |f| f.write output }