Garmin Forerunner TCX file processing

schacon (Scott Chacon) — Wed, 21 Mar 2007 19:05:29 GMT
This is a small ruby file I wrote to process the TCX file that I can download from MotionBased website that is processed from the data off my Garmin Forerunner 305. It processes the XML file and generates a little badge/infographic that I can put on a website.


// insert code here..

require "date"

require "rexml/document"

require 'rubygems'

require 'RMagick'



class ForeRunner

  

  M2MI = 1609.344 # meters to miles

  MINIMUM_LAP_TIME = 300 # minimum seconds to count as a full lap

  

  attr_accessor :laps, :total_time, :distance, :calories

  

  def initialize(file)

    @source_doc = REXML::Document.new file

    

    @laps = 0

    @lap_times = Array.new

    @lap_bpm = Array.new

    @full_laps = 0



    @total_time = 0    

    @distance = 0

    @calories = 0

    @map_data = []

    

    self.process_file  

  end

  

  def generate_infographic(output_filename)

    canvas = Magick::Image.new(250, 80)

    map_size = 50

    map_color = 'green'



    max_lap_height = 25

    

    gc = Magick::Draw.new



    # Draw ellipse

    gc.stroke('grey50')

    gc.stroke_width(2)

    gc.fill_opacity(0)



    # draw the relative lap times

    lap = 0

    max_time = @lap_times.max

    @lap_times.each do |s|

      lap += 1

      x = 10 + (lap * 5)

      y = 60 - (s / (max_time / max_lap_height))

      gc.line(x, 60, x, y)

    end



    #draw the heartbeat avg

    gc.stroke('#c9a')

    

    lap = 0

    lx = nil

    ly = nil

    max_bpm = @lap_bpm.max

    min_bpm = @lap_bpm.min

    

    max_bpm_height = 18

    

    @lap_bpm.each do |s|

      lap += 1

      x = 10 + (lap * 5)

      y = 21 - ( (s - min_bpm) / ((max_bpm - min_bpm) / max_bpm_height))

      if !lx

        lx = x

        ly = y

      end



      gc.line(lx, ly, x, y)



      lx = x

      ly = y

    end



    # draw the map

    lat_diff = (@map_data['max_lat'] - @map_data['min_lat']).abs

    lon_diff = (@map_data['max_lon'] - @map_data['min_lon']).abs



    lat_off = lat_diff / map_size

    lon_off = lon_diff / map_size

    

    gc.fill(map_color)

    @map_data['map_data'].each do |i|

      lt = (map_size - ((i[0] - @map_data['min_lat']) / lat_off)).round

      lg = ((i[1] - @map_data['min_lon']) / lon_off).round

      gc.point((240 - map_size) + lg, (65 - map_size) + lt)

    end



    # Annotate

    gc.stroke('transparent')

    gc.fill('black')

    gc.text(120, 15, @distance.to_s[0, 5] + ' mi')

    gc.text(120, 30, (@total_time / 60 / 60).to_s[0, 4] + ' hr')

    gc.text(120, 45, @calories.to_s + ' cal')



    gc.fill('#555')

    total_hr = 0 

    @lap_bpm.each { |hr| total_hr += hr }

    gc.text(15, 32, 'avg bpm: ' + (total_hr / @laps).round.to_s)

    gc.text(15, 75, 'avg pace: ' + ((@total_time / @full_laps) / 60).to_s[0, 4] + ' min/lap')



    gc.draw(canvas)

    canvas.write(output_filename)

  end

  

  protected 

  

  def process_file

    @source_doc.elements.each('TrainingCenterDatabase/Activities/Activity/Lap/*') do |element| 

      if element.name == "TotalTimeSeconds"

        @lap_times << element.text.to_f

        if element.text.to_f > 300  # for removing warmup and warmdown laps

          @total_time += element.text.to_f

          @full_laps += 1

        end

        @laps += 1

      end



      if element.name == "DistanceMeters" 

        @distance += (element.text.to_f / M2MI)

      end



      if element.name == "Calories" 

        @calories += element.text.to_f

      end



      if element.name == "AverageHeartRateBpm" 

        element.elements.each('Value') { |v| @lap_bpm << v.text.to_f }

      end

    end

    @map_data = self.generate_map_points

  end

  

  def generate_map_points  

    map = []



    max_lat = -300

    max_lon = -300

    min_lat = 300

    min_lon = 300



    @source_doc.elements.each('TrainingCenterDatabase/Activities/Activity/Lap/Track/Trackpoint/*') do |element|

      if element.elements['LatitudeDegrees']

        lat = element.elements['LatitudeDegrees'].text.to_f

        lon = element.elements['LongitudeDegrees'].text.to_f



        map << [lat, lon]

        max_lat = lat if (lat > max_lat) 

        max_lon = lon if (lon > max_lon) 

        min_lat = lat if (lat < min_lat) 

        min_lon = lon if (lon < min_lon) 

      end

    end

    {'map_data' => map, 'max_lat' => max_lat, 'min_lat' => min_lat, 'max_lon' => max_lon, 'min_lon' => min_lon}

  end

  



end





if ARGV[0].nil? 

  puts "This program takes one argument, a Garmin Forerunner TCX File"

  puts "Like this: run.rb filename.tcx"

  exit

end



output_filename = ARGV[0].gsub(/\.tcx$/, "-" + Time.now.strftime("%Y%m%d") + ".png")

puts "Generating Graph #{output_filename}"



fr = ForeRunner.new(File.new(ARGV[0]))

fr.generate_infographic(output_filename)
DZone Snippets: motionbased code

Garmin Forerunner TCX file processing
