Perform cosmologial corrections the right way around, thanks @wmfw23

SWIFTSIM · Nov 18, 2020 · 7533846 · 7533846
1 parent 8b6b793
commit 7533846
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Showing 2 changed files with 5 additions and 5 deletions.
diff --git a/swiftsimio/objects.py b/swiftsimio/objects.py
@@ -276,6 +276,8 @@ def __new__(
             flag to indicate whether using comoving coordinates
         """
 
+        cosmo_factor: cosmo_factor
+
         try:
             obj = super().__new__(
                 self,
@@ -346,7 +348,7 @@ def convert_to_comoving(self) -> None:
             # Best to just modify values as otherwise we're just going to have
             # to do a convert_to_units anyway.
             values = self.d
-            values *= self.cosmo_factor.a_factor
+            values /= self.cosmo_factor.a_factor
             self.comoving = True
 
     def convert_to_physical(self) -> None:
@@ -357,7 +359,7 @@ def convert_to_physical(self) -> None:
             # Best to just modify values as otherwise we're just going to have
             # to do a convert_to_units anyway.
             values = self.d
-            values /= self.cosmo_factor.a_factor
+            values *= self.cosmo_factor.a_factor
             self.comoving = False
         else:
             return

diff --git a/tests/test_physical_conversion.py b/tests/test_physical_conversion.py
@@ -12,7 +12,5 @@ def test_convert(filename):
     coords = data.gas.coordinates
     coords_physical = coords.to_physical()
 
-    assert array_equal(
-        coords / data.gas.coordinates.cosmo_factor.a_factor, coords_physical
-    )
+    assert array_equal(coords * data.metadata.a, coords_physical)
     return