def test_from_literature_does_not_exist(self):
"""
call Cosmology.from_literature with invalid source
:return:
"""
with pytest.raises(NotImplementedError):
Cosmology.from_literature(source="NonExistingData")
def test_from_literature_factory(self):
"""
ensure that all literature data sets are complete to create an instance
:return:
"""
for key in Cosmology.literature_values.keys():
Cosmology.from_literature(key)
def test_comoving_volume(self):
"""
Comoving volume
note: the values with curvature (1 and 2) differ from yt solutions;
implementation follows Hogg (1999)
"""
redshift = FloatType(4.69)
ref_volume1 = FloatType(
5.162427665378852e+85) # cgs # Om=0.3, Ol=0.6, Ok=0.1 h=0.7
ref_volume2 = FloatType(
5.674663557429024e+85) # cgs # Om=0.3, Ol=0.8, Ok=-0.1 h=0.7
ref_volume3 = FloatType(
5.411273810433006e+85) # cgs # Om=0.3, Ol=0.7, Ok=0.0 h=0.7
cosmo1 = Cosmology(hubble_constant=0.7,
omega_lambda=0.6,
omega_matter=0.3)
cosmo2 = Cosmology(hubble_constant=0.7,
omega_lambda=0.8,
omega_matter=0.3)
cosmo3 = Cosmology(hubble_constant=0.7,
omega_lambda=0.7,
omega_matter=0.3)
assert cosmo1.comoving_volume(redshift) == pytest.approx(ref_volume1,
rel=0.001)
assert cosmo2.comoving_volume(redshift) == pytest.approx(ref_volume2,
rel=0.001)
assert cosmo3.comoving_volume(redshift) == pytest.approx(ref_volume3,
rel=0.001)
def test_comoving_distance_transverse(self):
"""
Transverse comoving distance
"""
redshift = FloatType(4.69)
ref_distance1 = FloatType(
2.3774954250747463e+28) # cgs # Om=0.3, Ol=0.6, Ok=0.1 h=0.7
ref_distance2 = FloatType(
2.3024772762163336e+28) # cgs # Om=0.3, Ol=0.8, Ok=-0.1 h=0.7
ref_distance3 = FloatType(
2.3464085554485967e+28) # cgs # Om=0.3, Ol=0.7, Ok=0.0 h=0.7
cosmo1 = Cosmology(omega_lambda=FloatType(0.6),
omega_matter=FloatType(0.3),
hubble_constant=FloatType(0.7))
cosmo2 = Cosmology(omega_lambda=FloatType(0.8),
omega_matter=FloatType(0.3),
hubble_constant=FloatType(0.7))
cosmo3 = Cosmology(omega_lambda=FloatType(0.7),
omega_matter=FloatType(0.3),
hubble_constant=FloatType(0.7))
assert cosmo1.comoving_distance_transverse(redshift) == pytest.approx(
ref_distance1, rel=0.001)
assert cosmo2.comoving_distance_transverse(redshift) == pytest.approx(
ref_distance2, rel=0.001)
assert cosmo3.comoving_distance_transverse(redshift) == pytest.approx(
ref_distance3, rel=0.001)
def test_getattr(self):
"""
get dictionary with literature values directly
:return:
"""
my_cosmology = Cosmology()
print(my_cosmology.wmap9)
print(
my_cosmology._hubble_constant) # make sure this is still possible
print(my_cosmology['wmap9'])
print(Cosmology().planck2016)
def test_redshift_scalefactor_conversion(self):
"""
redshift to scalefactor, scalefactor to redshift
"""
redshift_reference = FloatType(2.4633)
scalefactor = Cosmology.scalefactor(redshift=redshift_reference)
redshift = Cosmology.redshift(scalefactor=scalefactor)
scalefactor_reference = 1.0 / (1.0 + redshift_reference)
assert scalefactor == pytest.approx(scalefactor_reference)
assert redshift == pytest.approx(redshift_reference)
def test_luminosity_distance(self):
"""
Luminosity distance
"""
redshift = FloatType(4.69)
ref_distance = FloatType(1.3665319230763794e+29) # cgs
cosmo = Cosmology.from_literature('planck2016')
assert cosmo.luminosity_distance(redshift) == pytest.approx(
ref_distance, rel=0.001)
def test_angular_diameter_distance(self):
"""
Angular diameter distance
"""
redshift = FloatType(4.69)
ref_distance = FloatType(4.2208046153686803e+27) # cgs
cosmo = Cosmology.from_literature('planck2016')
assert cosmo.angular_diameter_distance(redshift) == pytest.approx(
ref_distance, rel=0.001)
def test_comoving_distance_line_of_sight(self):
"""
Comoving distance
"""
redshift = FloatType(4.69)
ref_distance = FloatType(2.401637826144779e+28) # cgs
cosmo = Cosmology.from_literature('planck2016')
assert cosmo.comoving_distance_line_of_sight(
redshift) == pytest.approx(ref_distance, rel=0.001)
def test_peculiar_velocity(self):
"""
peculiar velocity
"""
v_pec = Cosmology.peculiar_velocity(redshift=FloatType(1.0),
redshift_observer=FloatType(0.5))
v_pec_reference = CLIGHT * 0.250
assert v_pec == pytest.approx(v_pec_reference)
def test_distance_modulus(self):
"""
distance modulus
"""
redshift = FloatType(4.69)
ref_distance = FloatType(1.3665319230763794e+29) # cgs
ref_dm = 5. * np.log10(ref_distance / 10. / PARSEC)
cosmo = Cosmology.from_literature('planck2016')
assert cosmo.distance_modulus(redshift) == pytest.approx(ref_dm,
rel=0.001)
def test_omega_curvature(self):
"""
Omega curvature
"""
o_m = FloatType(0.20)
o_l = FloatType(0.72)
my_cosmology = Cosmology(omega_matter=o_m, omega_lambda=o_l)
o_k = my_cosmology.omega_curvature
o_k_reference = 1.0 - o_m - o_l
assert o_k == pytest.approx(o_k_reference)
def test_critical_density(self):
"""
critical density
"""
h_0 = FloatType(0.6774)
my_cosmology = Cosmology(hubble_constant=h_0)
rho_c = my_cosmology.critical_density
hubble_0 = 100. * h_0 * 1.0e5 / MEGAPARSEC
rho_c_reference = 3.0 * hubble_0 * hubble_0 / 8.0 / np.pi / GRAVITY
assert rho_c == pytest.approx(rho_c_reference)
def test_hubble_distance(self):
"""
Hubble distance
"""
h_0 = FloatType(1.0)
my_cosmology = Cosmology(hubble_constant=h_0)
d_h = my_cosmology.hubble_distance
hubble_0 = 100. * h_0 * 1.0e5 / MEGAPARSEC
d_h_reference = CLIGHT / hubble_0
assert d_h == pytest.approx(d_h_reference)
def test_hubble_time(self):
"""
Hubble time
"""
h_0 = FloatType(1.0)
my_cosmology = Cosmology(hubble_constant=h_0)
t_h = my_cosmology.hubble_time
hubble_0 = 100. * h_0 * 1.0e5 / MEGAPARSEC
t_h_reference = 1.0 / hubble_0
assert t_h == pytest.approx(t_h_reference)
def test_lookback_time(self):
"""
Lookback time; compare to some pre-calculated ones (used yt to calculate it)
"""
redshifts = np.array(
[0.0, 0.25, 0.5, 0.75, 1.0, 2.25, 3.75, 4.34, 5.0, 7.0, 1100.0],
dtype=FloatType)
lookback_ref_p16 = np.array([
0.0, 3.0351346358407234, 5.193918814993813, 6.7653096884483475,
7.93569077168917, 10.87878447278143, 12.136004047592554,
12.403029538446914, 12.62666394724965, 13.03808995523595,
13.802244387905864
],
dtype=FloatType)
cosmo = Cosmology.from_literature(source="planck2016")
lookback = []
for redshift in redshifts:
lookback.append(cosmo.lookback_time(redshift) / SEC_PER_GIGAYEAR)
assert np.array(lookback) == pytest.approx(lookback_ref_p16)
def test_init(self):
"""
initialization via constructor
:return:
"""
Cosmology(hubble_constant=FloatType(0.7))