nv1t · August 29, 2013 18:33 · Jan 26, 2009
diff --git a/gistfile1.py b/gistfile1.py
@@ -0,0 +1,103 @@
+# NMEA to GPX converter
+# Peter Pearson
+# version 0.11
+
+import csv
+import sys
+import time
+from time import strftime
+
+def convert_dms_to_dec(value, dir):
+	dPos = value.find(".")
+
+	mPos = dPos - 2
+	ePos = dPos
+
+	main = float(value[:mPos])	
+	min1 = float(value[mPos:])
+
+#	print "degrees:'%s', minutes:'%s'\n" % (main, min1)
+
+	newval = float(main) + float(min1)/float(60)
+
+	if dir == "W":
+		newval = -newval
+	elif dir == "S":
+		newval = -newval
+
+	return newval
+
+def format_coord(value):
+	return "%.9f" % float(round(value, 8))
+
+def format_time(value):
+	pre = strftime("%Y-%m-%dT") #"2007-04-15T"
+	hour = value[:2]
+	minute = value[2:4]
+	second = value[4:6]
+	timeval = pre + hour + ":" + minute + ":" + second + "Z"
+	return timeval
+
+def convert(inputfile, outputfile):
+	reader = csv.reader(open(inputfile, "rb"))
+	file = open(outputfile, 'w+')
+
+	file.write("<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<gpx version=\"1.0\" creator=\"nmea_conv\"\nxmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xmlns=\"http://www.topografix.com/GPX/1/0\"\nxsi:schemaLocation=\"http://www.topografix.com/GPX/1/0 http://www.topografix.com/GPX/1/0/gpx.xsd\">\n")
+
+	points = []
+	count = 0
+	minlat = 90
+	maxlat = -90
+	minlon = 180
+	maxlon = -180
+
+	for row in reader:
+		type = row[0]
+		if type == "$GPGGA":
+                        lat = convert_dms_to_dec(row[2], row[3])
+			lon = convert_dms_to_dec(row[4], row[5])
+
+                        # ignore dodgy values - safe to do, as it's unlikely I'm going to be in the South Atlantic anytime soon
+			if lat == 0.0 && lon == 0.0:
+                            continue
+
+			points.append([])
+			points[count].append(row[1])
+
+			if lat < minlat:
+				minlat = lat
+			if lat > maxlat:
+				maxlat = lat
+			if lon < minlon:
+				minlon = lon
+			if lon > maxlon:
+				maxlon = lon
+
+			points[count].append(lat)
+			points[count].append(lon)
+
+			points[count].append(row[9])
+			count += 1
+
+	print "Points: '%i'" % (count)
+
+	strbounds = "<bounds minlat=\"" + format_coord(minlat) + "\" minlon=\"" + format_coord(minlon) + "\" maxlat=\"" + format_coord(maxlat) + "\" maxlon=\"" + format_coord(maxlon) + "\"/>\n<trk>\n<trkseg>\n"
+	file.write(strbounds)
+
+	for point in range(count):
+		time = points[point][0]
+		lat_val = points[point][1]
+		long_val = points[point][2]
+		elev = points[point][3]
+
+		strElev = "%.4f" % float(elev)
+
+		strtrkpt = "<trkpt lat=\"" + format_coord(lat_val) + "\" lon=\"" + format_coord(long_val) + "\">\n  <ele>" + strElev + "</ele>\n<time>" + format_time(time) + "</time>\n</trkpt>\n"
+		file.write(strtrkpt)
+
+	file.write("</trkseg>\n</trk>\n</gpx>\n")
+	file.close()
+
+inputfile, outputfile = sys.argv[1], sys.argv[2]
+convert(inputfile,outputfile)
+print "Done!"