def _set_units(self, ds, base_units):
if ds is not None:
if getattr(ds, "cosmological_simulation", False):
self.hubble_constant = ds.hubble_constant
self.current_redshift = ds.current_redshift
attrs = (
"length_unit",
"mass_unit",
"time_unit",
"velocity_unit",
"magnetic_unit",
)
cgs_units = ("cm", "g", "s", "cm/s", "gauss")
for unit, attr, cgs_unit in zip(base_units, attrs, cgs_units):
if unit is None:
if ds is not None:
u = getattr(ds, attr, None)
elif attr == "velocity_unit":
u = self.length_unit / self.time_unit
elif attr == "magnetic_unit":
u = np.sqrt(4.0 * np.pi * self.mass_unit /
(self.time_unit**2 * self.length_unit))
else:
u = cgs_unit
else:
u = unit
if isinstance(u, str):
uq = YTQuantity(1.0, u)
elif isinstance(u, numeric_type):
uq = YTQuantity(u, cgs_unit)
elif isinstance(u, YTQuantity):
uq = u.copy()
elif isinstance(u, tuple):
uq = YTQuantity(u[0], u[1])
else:
uq = None
if uq is not None and hasattr(self, "hubble_constant"):
# Don't store cosmology units
atoms = {str(a) for a in uq.units.expr.atoms()}
if str(uq.units).startswith(
"cm") or "h" in atoms or "a" in atoms:
uq.convert_to_cgs()
if uq is not None and uq.units.is_code_unit:
mylog.warning(
"Cannot use code units of '%s' "
"when creating a FITSImageData instance! "
"Converting to a cgs equivalent.",
uq.units,
)
uq.convert_to_cgs()
if attr == "length_unit" and uq.value != 1.0:
mylog.warning("Converting length units from %s to %s.", uq,
uq.units)
uq = YTQuantity(1.0, uq.units)
setattr(self, attr, uq)
def _set_units(self, ds, base_units):
attrs = (
"length_unit",
"mass_unit",
"time_unit",
"velocity_unit",
"magnetic_unit",
)
cgs_units = ("cm", "g", "s", "cm/s", "gauss")
for unit, attr, cgs_unit in zip(base_units, attrs, cgs_units):
if unit is None:
if ds is not None:
u = getattr(ds, attr, None)
elif attr == "velocity_unit":
u = self.length_unit / self.time_unit
elif attr == "magnetic_unit":
u = np.sqrt(
4.0
* np.pi
* self.mass_unit
/ (self.time_unit ** 2 * self.length_unit)
)
else:
u = cgs_unit
else:
u = unit
if isinstance(u, str):
uq = YTQuantity(1.0, u)
elif isinstance(u, numeric_type):
uq = YTQuantity(u, cgs_unit)
elif isinstance(u, YTQuantity):
uq = u.copy()
elif isinstance(u, tuple):
uq = YTQuantity(u[0], u[1])
else:
uq = None
if uq is not None and uq.units.is_code_unit:
mylog.warning(
"Cannot use code units of '%s' " % uq.units
+ "when creating a FITSImageData instance! "
"Converting to a cgs equivalent."
)
uq.convert_to_cgs()
if attr == "length_unit" and uq.value != 1.0:
mylog.warning(
"Converting length units " "from %s to %s." % (uq, uq.units)
)
uq = YTQuantity(1.0, uq.units)
setattr(self, attr, uq)