fix cosmo unit discovery

src/scida/configfiles/simulations.yaml

@@ -121,15 +121,18 @@ data:
         - Illustris100
       identifiers:
         name_contains: "Illustris-1"  # can only rely on path name in lack of metadata...
+      unitfile: [ units/illustris.yaml ]  # cosmology explicitly needed for catalogs
 
   Illustris-2:
       <<: *illustris_params
       identifiers:
         name_contains: "Illustris-2"
+      unitfile: [ units/illustris.yaml ]
   Illustris-3:
       <<: *illustris_params
       identifiers:
         name_contains: "Illustris-3"
+      unitfile: [ units/illustris.yaml ]
 
   EAGLEtype:
       identifiers:

src/scida/customs/arepo/dataset.py

@@ -175,6 +175,8 @@ def load_catalog(
             fileprefix=prfx,
             units=self.withunits,
             ureg=ureg,
+            hints=self.hints,
+            metadata_raw_parent=self._metadata_raw,
         )
         if "Redshift" in self.catalog.header and "Redshift" in self.header:
             z_catalog = self.catalog.header["Redshift"]

src/scida/interfaces/mixins/cosmology.py

@@ -28,19 +28,30 @@ def __init__(self, *args, **kwargs):
             self._mixins.append(self._mixin_name)
         else:
             self._mixins = [self._mixin_name]
+        self.hints["cosmological"] = True
+
+        # now call the parent class constructor as we need the metadata_raw
         super().__init__(*args, **kwargs)
+
         metadata_raw = self._metadata_raw
         c = get_cosmology_from_rawmetadata(metadata_raw)
+        # sometimes, we want to inherit the cosmology from the parent dataset (e.g. catalogs for snapshots)
+        if c is None and "metadata_raw_parent" in kwargs:
+            c = get_cosmology_from_rawmetadata(kwargs["metadata_raw_parent"])
         self.cosmology = c
+        if c is not None:
+            self.hints["cosmology"] = c
         z = get_redshift_from_rawmetadata(metadata_raw)
-        self.hints["cosmological"] = True
         self.redshift = z
         self.metadata["redshift"] = self.redshift
+
         if hasattr(self, "ureg"):
             ureg = self.ureg
             with ignore_warn_redef(ureg):
                 if c is not None:
                     ureg.define("h = %s" % str(c.h))
+                elif "cosmology" in self.hints:
+                    ureg.define("h = %s" % str(self.hints["cosmology"].h))
                 if z is not None:
                     a = 1.0 / (1.0 + z)
                     ureg.define("a = %s" % str(float(a)))
@@ -97,6 +108,10 @@ def validate(cls, metadata: dict, *args, **kwargs):
             if np.isclose(time, 1.0 / (1.0 + redshift)):
                 # print("Legacy metadata detected for Cosmology Mixin detection.")
                 valid = True
+        # sometimes, we have a cosmological runs if we only have the redshift key but no time key (e.g. LGalaxies)
+        if "/Header" in metadata and "Redshift" in metadata["/Header"]:
+            if "Time" not in metadata["/Header"]:
+                valid = True
 
         # in case of SWIFT, we have the "Cosmological run" key in the "Cosmology" group set to 1
         if "/Cosmology" in metadata:

src/scida/interfaces/mixins/units.py

@@ -262,7 +262,6 @@ def _get_default_units(mode: str, ureg: pint.UnitRegistry) -> dict:
             "velocity": ureg.cm / ureg.s,
             "time": ureg.s,
         }
-
     # common factors in cosmological simulations
     if "h" in ureg:
         udict["h"] = str_to_unit("h", ureg)
@@ -294,6 +293,10 @@ def new_unitregistry() -> UnitRegistry:
     """
     ureg = UnitRegistry(autoconvert_offset_to_baseunit=True)
     ureg.define("unknown = 1.0")
+    # we remove the hours "h" unit, so we cannot confuse it with the Hubble factor
+    del ureg._units["h"]
+    # we remove the year "a" unit, so we cannot confuse it with the scale factor
+    del ureg._units["a"]
     return ureg
 
 
@@ -667,7 +670,10 @@ def check_unit_mismatch(unit, unit_metadata, override=False, path="", logger=log
     bool:
         Whether the units agree.
     """
-    without_units = unit == "none" or unit_metadata == "none"  # explicitly no units
+    without_units = isinstance(unit, str) and unit == "none"
+    without_units |= (
+        isinstance(unit_metadata, str) and unit_metadata == "none"
+    )  # explicitly no units
     if unit is not None and unit_metadata is not None:
         msg = None
         if without_units and unit == unit_metadata: