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copied!<p>You may still be able to use data portions of GPSD, rather than writing something from scratch. The following code is from the GPSD source and has a module for making paths from streams of GPS data (and then getting the path length and whatnot)</p> <p><a href="http://code.google.com/p/python-gpsd/source/browse/src/nmea/track.py" rel="nofollow">http://code.google.com/p/python-gpsd/source/browse/src/nmea/track.py</a></p> <pre><code>class Track(object): def __init__(self, recordDelay=10, maxSize=3600, ignoreDuplicates=True, duplicateRange=0.0001): """ Constructor The default values allow for 10 hours worth of data recorded at 10 second intervals. recordDelay - Delay between recording data points maxSize - Maximum number of points to record ignoreDuplicates - Ignore entries that are very similar (ie moved a minimal distance) duplicateRange - Varience range within a duplicate is detected (adjust to account for subtle gps position drift) """ self.recordDelay = recordDelay self.maxSize = maxSize self.ignoreDuplicates = ignoreDuplicates self.duplicateRange = duplicateRange self.positions = [] self.latest = None def append(self, position, heading, timeStamp=None): """ Append position and heading information """ if timeStamp is None: timeStamp = datetime.utcnow() self.latest = (timeStamp, position, heading) if len(self.positions): last = self.positions[0] else: last = None # Make sure we re in range if last is None or (timeStamp - last[0]).seconds >= self.recordDelay: self.positions.insert(0, self.latest) self.latest = None # Clear extra data if len(self.positions) > self.maxSize: pass def clear(self): """ Clear all items from track """ self.positions = [] self.latest = None def __len__(self): """ Return the length of the track """ if self.latest is None: return len(self.positions) return len(self.positions) + 1 def __getslice__(self, i, j): return self.positions[i:j] def __getitem__(self, i): return self.positions[i] def get_latest(self): if self.latest is None and len(self.positions) > 0: return self.positions def get_by_time(self, timeRange, now=datetime.utcnow()): """ Returns the last n items within the time range """ result = [] if self.latest is not None: result.append(self.latest) for position in self.positions: if (now - position[0]).seconds > timeRange: break result.append(position) return result </code></pre>

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