Ruby program to convert GPX to KML

GarminのeTrexでtrackを記録したGISデータ（GPX形式）をGoogleEarthで見るのに、KML形式に変換するRubyプログラムです。前はそうした変換をGPSBabelというソフトでやっていたのですが、出力したKMLファイルがあまりきれいではなかったので、Rubyで作ってみました。(mybasic.rbが必要です。)

#!/usr/bin/ruby
=begin
trk2path.rb by Tomboya
>ruby trk2path.rb input.gpx
=end

require "~/myprg/ruby/mybasic"
require "rexml/document"

fname = ARGV[0]
data = REXML::Document.new(File.new(fname))
document = REXML::Document.new

kml = document.add_element("kml")
kml.add_namespace("http://earth.google.com/kml/2.0")

kml = kml.add_element("Document")
kml.add_element("name").text = fname

stylemap=kml.add_element("StyleMap")
stylemap.attributes["id"]="msn_ylw-pushpin"
  pair = stylemap.add_element("Pair")
  pair.add_element("key").text="normal"
  pair.add_element("styleUrl").text="sn_ylw-pushpin"
  pair = stylemap.add_element("Pair")
  pair.add_element("key").text="highlight"
  pair.add_element("styleUrl").text="sh_ylw-pushpin"

style=kml.add_element("Style")
style.attributes["id"]="sh_ylw-pushpin"
style.add_element("IconStyle").add_element("scale").text=1.2
  linestyle=style.add_element("LineStyle")
  linestyle.add_element("color").text = "ff1e15ff"
  linestyle.add_element("width").text = 3

style=kml.add_element("Style")
style.attributes["id"]="sn_ylw-pushpin"
  linestyle=style.add_element("LineStyle")
  linestyle.add_element("color").text = "ff10fcff"
  linestyle.add_element("width").text = 3

data.elements.each("gpx/trk"){|trk|
  cord=""
  time=[]
  placemark=kml.add_element("Placemark")
  placemark.add_element("name").text = trk.elements["name"].text

  linestring=placemark.add_element("LineString")
  linestring.add_element("tessellate").text = 1

  coordinates=linestring.add_element("coordinates")
  trk.elements.each("trkseg/trkpt"){|trkpt|
    cord << trkpt.attributes["lon"] << ","
    cord << trkpt.attributes["lat"] << ","
    cord << trkpt.elements["ele"].text << " "
    time << trkpt.elements["time"].text unless trkpt.elements["time"].nil?
  }
  coordinates.text=cord
  placemark.add_element("description").text = "FROM #{time[0]} TO #{time[time.size-1]}" unless time==[]
  placemark.add_element("styleUrl").text = "#msn_ylw-pushpin"
}

out=''
kml.write(out, 0, false, true)
mywrite("#{fname.split(".")[0]}.kml",[out])