diff --git a/tupak/gw/conversion.py b/tupak/gw/conversion.py
index 8a8c88444a98cd50aace5c5dc4862ed184f6b66e..6be1fcaea8408fbdde62d5157627ef854c6e27a5 100644
--- a/tupak/gw/conversion.py
+++ b/tupak/gw/conversion.py
@@ -169,6 +169,71 @@ def convert_to_lal_binary_black_hole_parameters(parameters, search_keys, remove=
return converted_parameters, added_keys
+def convert_to_lal_binary_neutron_star_parameters(parameters, search_keys, remove=True):
+ """
+ Convert parameters we have into parameters we need.
+
+ This is defined by the parameters of tupak.source.lal_binary_black_hole()
+
+
+ Mass: mass_1, mass_2
+ Spin: a_1, a_2, tilt_1, tilt_2, phi_12, phi_jl
+ Extrinsic: luminosity_distance, theta_jn, phase, ra, dec, geocent_time, psi
+
+ This involves popping a lot of things from parameters.
+ The keys in added_keys should be popped after evaluating the waveform.
+
+ Parameters
+ ----------
+ parameters: dict
+ dictionary of parameter values to convert into the required parameters
+ search_keys: list
+ parameters which are needed for the waveform generation
+ remove: bool, optional
+ Whether or not to remove the extra key, necessary for sampling, default=True.
+
+ Return
+ ------
+ converted_parameters: dict
+ dict of the required parameters
+ added_keys: list
+ keys which are added to parameters during function call
+ """
+ converted_parameters = parameters.copy()
+ converted_parameters, added_keys = convert_to_lal_binary_black_hole_parameters(
+ converted_parameters, search_keys, remove=remove)
+
+ if 'lambda_1' not in search_keys and 'lambda_2' not in search_keys:
+ if 'delta_lambda' in converted_parameters.keys():
+ converted_parameters['lambda_1'], converted_parameters['lambda_2'] =\
+ lambda_tilde_delta_lambda_to_lambda_1_lambda_2(
+ converted_parameters['lambda_tilde'], parameters['delta_lambda'],
+ converted_parameters['mass_1'], converted_parameters['mass_2'])
+ added_keys.append('lambda_1')
+ added_keys.append('lambda_2')
+ elif 'lambda_tilde' in converted_parameters.keys():
+ converted_parameters['lambda_1'], converted_parameters['lambda_2'] =\
+ lambda_tilde_to_lambda_1_lambda_2(
+ converted_parameters['lambda_tilde'],
+ converted_parameters['mass_1'], converted_parameters['mass_2'])
+ added_keys.append('lambda_1')
+ added_keys.append('lambda_2')
+ if 'lambda_2' not in converted_parameters.keys():
+ converted_parameters['lambda_2'] =\
+ converted_parameters['lambda_1']\
+ * converted_parameters['mass_1']**5\
+ / converted_parameters['mass_2']**5
+ added_keys.append('lambda_2')
+ elif converted_parameters['lambda_2'] is None:
+ converted_parameters['lambda_2'] =\
+ converted_parameters['lambda_1']\
+ * converted_parameters['mass_1']**5\
+ / converted_parameters['mass_2']**5
+ added_keys.append('lambda_2')
+
+ return converted_parameters, added_keys
+
+
def total_mass_and_mass_ratio_to_component_masses(mass_ratio, total_mass):
"""
Convert total mass and mass ratio of a binary to its component masses.
@@ -358,6 +423,87 @@ def mass_1_and_chirp_mass_to_mass_ratio(mass_1, chirp_mass):
return mass_ratio
+def lambda_tilde_delta_lambda_to_lambda_1_lambda_2(
+ lambda_tilde, delta_lambda, mass_1, mass_2):
+ """
+ Convert from dominant tidal terms to individual tidal parameters.
+
+ See, e.g., Wade et al., https://arxiv.org/pdf/1402.5156.pdf.
+
+ Parameters
+ ----------
+ lambda_tilde: float
+ Dominant tidal term.
+ delta_lambda: float
+ Secondary tidal term.
+ mass_1: float
+ Mass of more massive neutron star.
+ mass_2: float
+ Mass of less massive neutron star.
+
+ Return
+ ------
+ lambda_1: float
+ Tidal parameter of more massive neutron star.
+ lambda_2: float
+ Tidal parameter of less massive neutron star.
+ """
+ eta = component_masses_to_symmetric_mass_ratio(mass_1, mass_2)
+ q = mass_2 / mass_1
+ coefficient_1 = (1 + 7 * eta - 31 * eta**2) * (1 + q**5)
+ coefficient_2 = (1 - 4 * eta)**0.5 * (1 + 9 * eta - 11 * eta**2)\
+ * (1 - q**0.5)
+ coefficient_3 = (1 - 4 * eta)**0.5\
+ * (1 - 13272 / 1319 * eta + 8944 / 1319 * eta**2)
+ coefficient_4 = (1 - 15910 / 1319 * eta + 32850 / 1319 * eta**2
+ + 3380 / 1319 * eta**3)
+ lambda_1 =\
+ (13 * lambda_tilde / 8 * (coefficient_3 - coefficient_4)
+ - 2 * delta_lambda * (coefficient_1 - coefficient_2))\
+ / ((coefficient_1 + coefficient_2) * (coefficient_3 - coefficient_4)
+ - (coefficient_1 - coefficient_2) * (coefficient_3 + coefficient_4))
+ lambda_2 =\
+ (13 * lambda_tilde / 8 * (coefficient_3 + coefficient_4)
+ - 2 * delta_lambda * (coefficient_1 + coefficient_2)) \
+ / ((coefficient_1 - coefficient_2) * (coefficient_3 + coefficient_4)
+ - (coefficient_1 + coefficient_2) * (coefficient_3 - coefficient_4))
+ return lambda_1, lambda_2
+
+
+def lambda_tilde_to_lambda_1_lambda_2(
+ lambda_tilde, mass_1, mass_2):
+ """
+ Convert from dominant tidal term to individual tidal parameters
+ assuming lambda_1 * mass_1**5 = lambda_2 * mass_2**5.
+
+ See, e.g., Wade et al., https://arxiv.org/pdf/1402.5156.pdf.
+
+ Parameters
+ ----------
+ lambda_tilde: float
+ Dominant tidal term.
+ mass_1: float
+ Mass of more massive neutron star.
+ mass_2: float
+ Mass of less massive neutron star.
+
+ Return
+ ------
+ lambda_1: float
+ Tidal parameter of more massive neutron star.
+ lambda_2: float
+ Tidal parameter of less massive neutron star.
+ """
+ eta = component_masses_to_symmetric_mass_ratio(mass_1, mass_2)
+ q = mass_2 / mass_1
+ lambda_1 = 13 / 8 * lambda_tilde / (
+ (1 + 7 * eta - 31 * eta**2) * (1 + q**5)
+ + (1 - 4 * eta)**0.5 * (1 + 9 * eta - 11 * eta**2) * (1 - q**0.5)
+ )
+ lambda_2 = lambda_1 / q**0.5
+ return lambda_1, lambda_2
+
+
def generate_all_bbh_parameters(sample, likelihood=None, priors=None):
"""
From either a single sample or a set of samples fill in all missing BBH parameters, in place.