def eta_mass1_to_mass2(eta, mass1, return_mass_heavier=False, force_real=True):
"""
This function takes values for eta and one component mass and returns the
second component mass. Similar to mchirp_mass1_to_mass2 this requires
finding the roots of a quadratic equation. Basically:
eta m2^2 + (2 eta - 1)m1 m2 + \eta m1^2 = 0
This has two solutions which correspond to mass1 being the heavier mass
or it being the lighter mass. By default the value corresponding to
mass1 > mass2 is returned. Use the return_mass_heavier kwarg to invert this
behaviour.
"""
return conversions.mass_from_knownmass_eta(mass1, eta,
known_is_secondary=return_mass_heavier, force_real=force_real)
def eta_mass1_to_mass2(eta, mass1, return_mass_heavier=False, force_real=True):
"""
This function takes values for eta and one component mass and returns the
second component mass. Similar to mchirp_mass1_to_mass2 this requires
finding the roots of a quadratic equation. Basically:
eta m2^2 + (2 eta - 1)m1 m2 + \eta m1^2 = 0
This has two solutions which correspond to mass1 being the heavier mass
or it being the lighter mass. By default the value corresponding to
mass1 > mass2 is returned. Use the return_mass_heavier kwarg to invert this
behaviour.
"""
return conversions.mass_from_knownmass_eta(mass1, eta,
known_is_secondary=return_mass_heavier, force_real=force_real)
