Daniel's pollution and position converter

convert.rb

#!/usr/bin/env ruby

# Script to load GPS and CO2 data and normalize the data
# the position data in a file "run.xml"
# pollution in a file "pollution.txt"

require 'nokogiri'
require 'fastercsv'
require 'active_support'

run_csv = []
run_data = Nokogiri::XML File.read('run.xml')
run_data.remove_namespaces!

run_data.xpath('//trkpt').each do |point|
  row = []
  row << Time.parse(point.xpath('time').text).utc
  row << point.attr('lat')
  row << point.attr('lon')
  row << point.xpath('ele').text
  run_csv << row
end

# puts run_csv.join("\n")

pollution_table = []
pollution_data = FasterCSV.parse File.read('pollution.txt')
pollution_data.shift # loose the header

pollution_data.each do |row|
  date, time = row[1].split(" ")
  timestamp = Time.parse "#{date.split("/").reverse.join("/")} #{time}"
  pollution_table << [(timestamp+4.hours).utc, row[2]]
end

# puts pollution_table.join("\n")

start = run_csv[0][0]
finish = run_csv[-1][0]

range = start..finish
final = [["timestamp","lat","lon","ele","co2"].join(",")]

range.each do |p|
  row = [p,nil,nil,nil,nil]
  run = run_csv.detect {|r| r[0] == p} || []
  run.each_with_index do |c,i|
    row[i] = c
  end
  
  pol = pollution_table.detect {|r| r[0] == p} || []
  pol.shift
  pol.each_with_index do |c,i|
    row[i+4] = c
  end

  final << row.join(",")
end

puts final.join("\n")
File.open("out.csv","w") {|f| f << final.join("\n")}