Rewrite of PR 2: added metrics option and argparse cmdline parsing.

The PR was based on an earlier version of pytopo and reverted some
recent changes, so those parts needed to be redone from Marco's PR.

pytopo/MapUtils.py

@@ -7,6 +7,8 @@
 
 import math
 
+EARTH_RADIUS_MI = 3959.
+EARTH_RADIUS_KM = 6371.
 
 class MapUtils:
 
@@ -113,7 +115,7 @@ def ohstring(cls, num, numdigits):
 
     @classmethod
     def haversine_distance(cls, latitude_1, longitude_1,
-                           latitude_2, longitude_2):
+                           latitude_2, longitude_2, metric=False):
         """
         Haversine distance between two points, expressed in meters.
         From https://github.com/tkrajina/gpxpy/blob/master/gpxpy/geo.py
@@ -129,10 +131,11 @@ def haversine_distance(cls, latitude_1, longitude_1,
             math.sin(d_lon / 2) * math.sin(d_lon / 2) * \
             math.cos(lat1) * math.cos(lat2)
         c = 2 * math.atan2(math.sqrt(a), math.sqrt(1 - a))
-        EARTH_RADIUS = 3959.     # miles
-        d = EARTH_RADIUS * c
 
-        return d
+        if metric:
+            return EARTH_RADIUS_KM * c
+        else:
+            return EARTH_RADIUS_MI * c
 
     @classmethod
     def distance_on_unit_sphere(cls, lat1, long1, lat2, long2):

pytopo/trackstats.py

@@ -11,6 +11,7 @@
 import math
 import datetime
 import numpy
+import argparse
 
 from MapUtils import MapUtils
 
@@ -31,7 +32,7 @@
 lastele = -1
 
 
-def statistics(trackpoints, halfwin, beta):
+def statistics(trackpoints, halfwin, beta, metric):
     '''Accumulate statistics like mileage and total climb.
        Return a dictionary of stats collected.
     '''
@@ -81,15 +82,18 @@ def accumulate_climb(ele):
         t = datetime.datetime.strptime(t, '%Y-%m-%dT%H:%M:%SZ')
         lat =  float(lat)
         lon = float(lon)
-        ele = round(float(ele) * 3.2808399, 2)    # convert meters->feet
+        if metric:
+            ele = round(float(ele),2)
+        else:
+            ele = round(float(ele) * 3.2808399, 2)    # convert meters->feet
 
         if not lastlat or not lastlon:
             lastlat = lat
             lastlon = lon
             lasttime = t
             continue
 
-        dist = MapUtils.haversine_distance(lat, lon, lastlat, lastlon)
+        dist = MapUtils.haversine_distance(lat, lon, lastlat, lastlon, metric)
 
         delta_t = t - lasttime   # a datetime.timedelta object
         speed = dist / delta_t.seconds * 60 * 60    # miles/hour
@@ -193,54 +197,54 @@ def main():
         have_plt = False
         print "plt isn't installed; will print stats only, no plotting"
 
-    if len(sys.argv) < 2:
-        cmdname = os.path.basename(sys.argv[0])
-        print "%s version %s" % (cmdname, pytopo.__version__)
-        print "Usage: %s [-b beta] [-w halfwidth] file.gpx" % cmdname
-        print """  beta (default 2) and halfwidth (default 15)
-  are parameters for Kaiser window smoothing"""
-        return 1
-
-    # Default values that can be changed by commandline arguments:
-    beta = 2
-    halfwin = 15
-
-    # Look for flags:
-    args = sys.argv[1:]
-    while args[0][0] == '-':
-        if args[0] == '-b' and len(args) > 2:
-            beta = float(args[1])
-            args = args[2:]
-            continue
-        if args[0] == '-w' and len(args) > 2:
-            halfwin = int(args[1])
-            args = args[2:]
-            continue
-        print "Don't understand flag", args[0]
+    progname = os.path.basename(sys.argv[0])
+
+    parser = argparse.ArgumentParser(description='This parses track log files, in gpx format, and gives you a graph and a few statistics. ')
+    parser.add_argument('--version', action='version',
+                        version=pytopo.__version__)
+    parser.add_argument('-m', action="store_true", default=False,
+                        dest="metric",
+                        help='Use metric rather than US units')
+    parser.add_argument('-b', action="store", default=2, dest="beta", type=int,
+                        help='Kaiser window smoothing beta parameter (default: 2)')
+    parser.add_argument('-w', action="store", default=15, dest="halfwin",
+                        type=int, help='Kaiser window smoothing halfwidth parameter (default: 15)')
+    parser.add_argument('track_file', nargs='+')
+
+    results = parser.parse_args()
+    print results
+    beta = results.beta
+    halfwin = results.halfwin
+    metric = results.metric
+    track_files = results.track_file
 
     #
     # Read the trackpoints file:
     #
     trackpoints = pytopo.TrackPoints()
     try:
-        trackpoints.read_track_file(args[0])
+        trackpoints.read_track_file(track_files[0])
+        # XXX Read more than one file
     except IOError, e:
         print e
         #print dir(e)
         return e.errno
 
-    out = statistics(trackpoints, halfwin, beta)
+    out = statistics(trackpoints, halfwin, beta, metric)
 
     #
     # Print and plot the results:
     #
-    print "%.1f miles." % (out['Total distance'])
-    print "Raw total climb: %d'" % (int(out['Raw total climb']))
-    print "Smoothed climb: %d'" % out['Smoothed total climb']
+    climb_units = 'm' if metric else "'"
+    dist_units = 'km' if metric else 'mi'
+    print "%.1f %s" % (out['Total distance'], dist_units)
+    print "Raw total climb: %d%s" % (int(out['Raw total climb']), climb_units)
+    print "Smoothed climb: %d%s" % (out['Smoothed total climb'], climb_units)
     print "  from %d to %d" % (out['Lowest'], out['Highest'])
     print "%d minutes moving, %d stopped" % (int(out['Moving time'] / 60),
                                              int(out['Stopped time'] / 60))
-    print "Average speed moving: %.1f mph" % out['Average moving speed']
+    print "Average speed moving: %.1f %s/h" % (out['Average moving speed'],
+                                               dist_units)
     if not have_plt:
         return 0
 
@@ -254,13 +258,13 @@ def main():
     plt.plot(out['Distances'], out['Smoothed elevations'],
                color="red", label="smoothed (b=%.1f, hw=%d)" % (beta, halfwin))
 
-    title_string = "Elevation profile (" + str(round(out['Distances'][-1], 1)) \
-                   + " miles, " + str(int(out['Smoothed total climb'])) \
-                   + "' climb)"
+    title_string = "Elevation profile (%.1f %s, %d%s climb)" \
+                   % (out['Distances'][-1], dist_units,
+                      out['Smoothed total climb'], climb_units)
     plt.title(title_string)
 
     # Set the window titlebar to something other than "Figure 1"
-    plt.gcf().canvas.set_window_title("Ellie: " + args[0])
+    plt.gcf().canvas.set_window_title("%s: %s" % (progname, track_files[0]))
 
     plt.xlabel("miles")
 #    plt.get_current_fig_manager().window.set_title(os.path.basename(args[0] + ": " + title_string))