def from_bundle(cls, b, feature):
        """
        Initialize a Pulsation feature from the bundle.
        """

        feature_ps = b.get_feature(feature)
        freq = feature_ps.get_value('freq', unit=u.d**-1)
        radamp = feature_ps.get_value('radamp', unit=u.dimensionless_unscaled)
        l = feature_ps.get_value('l', unit=u.dimensionless_unscaled)
        m = feature_ps.get_value('m', unit=u.dimensionless_unscaled)
        teffext = feature_ps.get_value('teffext')

        GM = c.G.to('solRad3 / (solMass d2)').value*b.get_value(qualifier='mass', component=feature_ps.component, context='component', unit=u.solMass)
        R = b.get_value(qualifier='rpole', component=feature_ps.component, section='component', unit=u.solRad)

        tanamp = GM/R**3/freq**2

        return cls(radamp, freq, l, m, tanamp, teffext)
Initialize a Pulsation feature from the bundle.