/** Loads track segments of a GPX file, and returns them as a single line marker. */
public static List<Feature> loadData(PApplet p, String gpxFilename) {
List<Feature> trackFeatures = new ArrayList<Feature>();
// Load GPX file
XMLElement gpx = new XMLElement(p, gpxFilename);
// Create track with all track points
ShapeFeature trackFeature = new ShapeFeature(FeatureType.LINES);
XMLElement[] itemXMLElements = gpx.getChildren("trk/trkseg/trkpt");
for (int i = 0; i < itemXMLElements.length; i++) {
// Adds location for track point
float lat = itemXMLElements[i].getFloat("lat");
float lon = itemXMLElements[i].getFloat("lon");
Location location = new Location(lat, lon);
trackFeature.addLocation(location);
}
// Add time as property
XMLElement timeXMLElement = gpx.getChild("trk/time");
trackFeature.addProperty("time", timeXMLElement.getContent());
trackFeatures.add(trackFeature);
return trackFeatures;
}
/**
* Loads track segments of a GPX file, and returns them as a lines marker. Additionally, the speed
* is calculated between two points, and stored as property.
*
* <p>This varies from {@link GPXReader#loadData(PApplet, String)}.
*/
public static List<Feature> loadData(PApplet p, String gpxFilename) {
List<Feature> trackFeatures = new ArrayList<Feature>();
// Load GPX file
XMLElement gpx = new XMLElement(p, gpxFilename);
Calendar prevTime = null;
Location prevLocation = null;
// Create track with all track points
ShapeFeature trackFeature = new ShapeFeature(FeatureType.LINES);
List<Double> speedList = new ArrayList<Double>();
XMLElement[] itemXMLElements = gpx.getChildren("trk/trkseg/trkpt");
for (int i = 0; i < itemXMLElements.length; i++) {
// Adds location for track point
float lat = itemXMLElements[i].getFloat("lat");
float lon = itemXMLElements[i].getFloat("lon");
Location location = new Location(lat, lon);
// Calculates speed for track point
// Uses time span (h) and distance (km) to previous point to get km/h
double speed = 0;
try {
String timeStr = itemXMLElements[i].getChild("time").getContent();
// Replace "Z" for Zulu/GMT time with parseable hour offset
timeStr = timeStr.replaceAll("Z", "+0000");
Calendar time = StringUtils.parseIsoDateTime(timeStr);
if (prevTime != null) {
long timeMS = time.getTimeInMillis();
long timeDiff = timeMS - prevTime.getTimeInMillis();
double dist = GeoUtils.getDistance(location, prevLocation);
speed = dist / ((float) timeDiff / 1000 / 60 / 60);
}
prevTime = time;
prevLocation = location;
} catch (ParseException e) {
// println("Error:" + e);
}
speedList.add(speed);
trackFeature.addLocation(location);
}
trackFeature.putProperty("speedList", speedList);
trackFeatures.add(trackFeature);
return trackFeatures;
}
