fgrollier
diff --git a/‎astropy/cosmology/cosmology.py‎
Lines changed: 2 additions & 2 deletions b/‎astropy/cosmology/cosmology.py‎
Lines changed: 2 additions & 2 deletions
diff --git a/‎astropy/cosmology/tests/__init__.py‎ b/‎astropy/cosmology/tests/__init__.py‎
diff --git a/‎astropy/cosmology/tests/test_cosmology.py‎
Lines changed: 20 additions & 0 deletions b/‎astropy/cosmology/tests/test_cosmology.py‎
Lines changed: 20 additions & 0 deletions
@@ -165,12 +165,12 @@ def dm(self, z):
         else:
             return dh / sqrtOk * sin(sqrtOk * dc / dh)
 
-    def Da(self, z):
+    def da(self, z):
         """ Angular diameter distance in metres.  Ratio of an object's
         physical transverse size to its angular size in radians."""
         return self.dm(z) / (1. + z)
 
-    def Da2(self, z1, z2):
+    def da2(self, z1, z2):
         """ Angular diameter distance in metres between objects at 2
         redshifts.  Useful for gravitational lensing."""
         # does not work for negative curvature
 
@@ -0,0 +1,20 @@
+# Licensed under a 3-clause BSD style license - see LICENSE.rst
+
+from .. import cosmology
+
+def test_cosmology():
+    cosmo = cosmology.Cosmology(H0=70, Om=0.27 ,Ol=0.73)
+    z = 1
+    # Test values were taken from the following web cosmology
+    # calculators on 27th Feb 2012:
+
+    # Wright: http://www.astro.ucla.edu/~wright/CosmoCalc.html
+    # Kempner: http://www.kempner.net/cosmic.php
+    # iCosmos: http://www.icosmos.co.uk/index.html
+
+    # The order of values below is Wright, Kempner, iCosmos'
+    assert np.allclose(cosmo.dc(z), [3364.5, 3364.8, 3364.7988], rtol=1e-4)
+    assert np.allclose(cosmo.da(z), [1682.3, 1682.4, 1682.3994], rtol=1e-4)
+    assert np.allclose(cosmo.dl(z), [6729.2, 6729.6, 6729.5976], rtol=1e-4)
+    assert np.allclose(cosmo.tl(z), [7.841, 7.84178, 7.843],  rtol=1e-3)
+