def add_elevation(self, delta):
        mod_logging.debug('delta = %s' % delta)

        if not delta:
            return

        for track_point in self.points:
            if track_point.elevation is not None:
                track_point.elevation += delta
maximum likelihood estimator as starting values for Poisson distribution
dataset/ETHPy150Open tkrajina/gpxpy/gpxpy/gpx.py/GPXTrackSegment.add_elevation--crossover with--dataset/ETHPy150Open statsmodels/statsmodels/statsmodels/sandbox/distributions/sppatch.py/_fitstart_poisson