Check if Ob0 and Tcmb0 are non-zero for wiggle=T (#333)

skypy/power_spectrum/_eisenstein_hu.py

@@ -73,8 +73,18 @@ def transfer_with_wiggles(wavenumber, A_s, n_s, cosmology, kwmap=0.02):
 
     om0 = cosmology.Om0
     ob0 = cosmology.Ob0
+
+    if not ob0:
+        raise ValueError("Ob0 for input cosmology must be non-zero if "
+                         "wiggles = True")
+
     h0 = cosmology.H0.value / 100
     Tcmb0 = cosmology.Tcmb0.value
+
+    if not Tcmb0:
+        raise ValueError("Tcmb0 for input cosmology must be non-zero if"
+                         "wiggles = True")
+
     ak = wavenumber * h0
     om0h2 = om0 * h0**2
     ob0h2 = ob0 * h0**2

skypy/power_spectrum/tests/test_eisenstein_hu.py

@@ -1,6 +1,6 @@
 import numpy as np
 import pytest
-from astropy.cosmology import default_cosmology
+from astropy.cosmology import default_cosmology, FlatLambdaCDM
 from skypy.power_spectrum import eisenstein_hu
 
 
@@ -60,3 +60,17 @@ def test_eisenstein_hu():
     with pytest.raises(ValueError):
         eisenstein_hu(negative_wavenumber_array, A_s, n_s, cosmology, kwmap,
                       wiggle=False)
+
+    # Test for failure when cosmology has Ob0 = 0 and wiggle = True
+    zero_ob0_cosmology = FlatLambdaCDM(H0=70, Om0=0.3, Tcmb0=2.725)
+    wavenumber = np.logspace(-3, 1, num=5, base=10.0)
+    with pytest.raises(ValueError):
+        eisenstein_hu(wavenumber, A_s, n_s, zero_ob0_cosmology, kwmap,
+                      wiggle=True)
+
+    # Test for failure when cosmology has Tcmb = 0  and wiggle = True
+    zero_Tcmb0_cosmology = FlatLambdaCDM(H0=70, Om0=0.3, Ob0=0.05)
+    wavenumber = np.logspace(-3, 1, num=5, base=10.0)
+    with pytest.raises(ValueError):
+        eisenstein_hu(wavenumber, A_s, n_s, zero_Tcmb0_cosmology, kwmap,
+                      wiggle=True)