Routing grid

require 'rubygems' require 'yaml' CITIES = YAML::load_file(ARGV[0]) # average radius of the earth RADIUS = 6371010.0 # ratio of route to great circle distance to be considered "bad". this will # vary regionally (i.e: much higher in the mountains), so should be found by # experiment. FACTOR = 1.2 # calculate the great circle distance # from wikipedia: # arctan(sqrt((cos(phi_f) * sin(Delta_lambda))^2 + # (cos(phi_s) * sin(phi_f) - sin(phi_s) * cos(phi_f) * cos(Delta_lambda)^2)) / # (sin(phi_s) * sin(phi_f) + cos(phi_s) * cos(phi_f) * cos(Delta_lambda))) def great_circle(a, b) lambda = Math::PI * (a[1] - b[1]) / 180.0 phi_s = Math::PI * a[0] / 180.0 phi_f = Math::PI * b[0] / 180.0 sin_phi_s = Math::sin(phi_s) sin_phi_f = Math::sin(phi_f) sin_lambda = Math::sin(lambda) cos_phi_s = Math::cos(phi_s) cos_phi_f = Math::cos(phi_f) cos_lambda = Math::cos(lambda) sigma = Math::atan2(Math::sqrt((cos_phi_f * sin_lambda)**2 + (cos_phi_s * sin_phi_f - sin_phi_s * cos_phi_f * cos_lambda)**2), sin_phi_s * sin_phi_f + cos_phi_s * cos_phi_f * cos_lambda) return RADIUS * sigma end # define this as the success test - whether something worked or # not. return a :symbol, which will be used as the CSS class for # the table cell. def css_class(from, to, dist) if dist.nil? return :fail else if dist > FACTOR * great_circle(CITIES[from], CITIES[to]) return :bad elsif dist > 0.0 return :success else return :zero end end end city_dist = {} File.readlines(ARGV[1]).each do |line| from, to, dist = line.split(/;/) if dist == "NO ROUTE" dist = nil else dist = dist.to_f end if city_dist[from].nil? city_dist[from] = { to => dist } else city_dist[from][to] = dist end end city_names = CITIES.keys.sort puts <Routing grid END puts "" city_names.each do |to| to_pos = CITIES[to] url = "http://maps.cloudmade.com/?lat=#{to_pos[0]}&lng=#{to_pos[1]}&zoom=5" puts "" end puts "" counters = {} city_names.each do |from| from_pos = CITIES[from] url = "http://maps.cloudmade.com/?lat=#{from_pos[0]}&lng=#{from_pos[1]}&zoom=5" puts "" city_names.each do |to| to_pos = CITIES[to] dist = city_dist[from][to] cc = css_class(from, to, dist) counters[cc] = (counters[cc] || 0) + 1 url = "http://maps.cloudmade.com/?directions=#{[from_pos,to_pos].flatten.join(',')}&lat=#{0.5*(from_pos[0]+to_pos[0])}&lng=#{0.5*(from_pos[1]+to_pos[1])}&zoom=5" if dist.nil? puts "" else puts "" end end puts "" end puts "

	#{to}
#{from}	FAIL	#{dist}

" total = city_names.length ** 2 counters.each do |cc, n| puts "

Class #{cc}: #{n} of #{total} (#{(100.0*n)/total}%)

" end puts ""