def start(self): first = self.features[0] if first is None: raise Exception() return map_coord(first.mz, first.start_time)
def start(self): first = self.features[0] if first is None: raise Exception() return map_coord(first.mz, first.start_time)
def end(self): for last in reversed(self.features): if last is None: continue return map_coord(last.mz, last.end_time)
def end(self): for last in reversed(self.features): if last is None: continue return map_coord(last.mz, last.end_time)