xarray.DataArray.astropy.to¶

DataArray.astropy.to(units=None, equivalencies=None, **unit_kwargs)¶

convert the quantities in a DataArray

Parameters:

units (unit-like or mapping of hashable to unit-like, optional) – The units to convert to. If a unit name or astropy.units.Unit object, convert the DataArray’s data. If a dict-like, it has to map a variable name to a unit name or astropy.units.Unit object.
equivalencies (list) – A list of equivalence pairs to try if the units are not directly convertible. See Equivalencies. This list is in addition to possible global defaults set by, e.g., astropy.units.set_enabled_equivalencies(). Use None to turn off all equivalencies.
**unit_kwargs – The kwargs form of units. Can only be used for variable names that are strings and valid python identifiers.

Returns:

object – A new object with converted units.

Return type:

DataArray

Examples

>>> da = xr.DataArray(
...     data=np.linspace(0, 1, 5) * u.m,
...     coords={"u": ("x", np.arange(5) * u.s)},
...     dims="x",
...     name="arr",
... )
>>> da
<xarray.DataArray 'arr' (x: 5)> Size: 40B
<Quantity [0.  , 0.25, 0.5 , 0.75, 1.  ] m>
Coordinates:
    u        (x) float64 40B [s] 0.0 1.0 2.0 3.0 4.0
Dimensions without coordinates: x

Convert the data

>>> da.astropy.to("mm")
<xarray.DataArray 'arr' (x: 5)> Size: 40B
<Quantity [   0.,  250.,  500.,  750., 1000.] mm>
Coordinates:
    u        (x) float64 40B [s] 0.0 1.0 2.0 3.0 4.0
Dimensions without coordinates: x
>>> da.astropy.to(u.mm)
<xarray.DataArray 'arr' (x: 5)> Size: 40B
<Quantity [   0.,  250.,  500.,  750., 1000.] mm>
Coordinates:
    u        (x) float64 40B [s] 0.0 1.0 2.0 3.0 4.0
Dimensions without coordinates: x
>>> da.astropy.to({da.name: "mm"})
<xarray.DataArray 'arr' (x: 5)> Size: 40B
<Quantity [   0.,  250.,  500.,  750., 1000.] mm>
Coordinates:
    u        (x) float64 40B [s] 0.0 1.0 2.0 3.0 4.0
Dimensions without coordinates: x

Convert coordinates

>>> da.astropy.to({"u": u.ms})
<xarray.DataArray 'arr' (x: 5)> Size: 40B
<Quantity [0.  , 0.25, 0.5 , 0.75, 1.  ] m>
Coordinates:
    u        (x) float64 40B [ms] 0.0 1e+03 2e+03 3e+03 4e+03
Dimensions without coordinates: x
>>> da.astropy.to(u="ms")
<xarray.DataArray 'arr' (x: 5)> Size: 40B
<Quantity [0.  , 0.25, 0.5 , 0.75, 1.  ] m>
Coordinates:
    u        (x) float64 40B [ms] 0.0 1e+03 2e+03 3e+03 4e+03
Dimensions without coordinates: x

Convert both simultaneously

>>> da.astropy.to("mm", u="ms")
<xarray.DataArray 'arr' (x: 5)> Size: 40B
<Quantity [   0.,  250.,  500.,  750., 1000.] mm>
Coordinates:
    u        (x) float64 40B [ms] 0.0 1e+03 2e+03 3e+03 4e+03
Dimensions without coordinates: x
>>> da.astropy.to({"arr": u.mm, "u": u.ms})
<xarray.DataArray 'arr' (x: 5)> Size: 40B
<Quantity [   0.,  250.,  500.,  750., 1000.] mm>
Coordinates:
    u        (x) float64 40B [ms] 0.0 1e+03 2e+03 3e+03 4e+03
Dimensions without coordinates: x
>>> da.astropy.to(arr="mm", u="ms")
<xarray.DataArray 'arr' (x: 5)> Size: 40B
<Quantity [   0.,  250.,  500.,  750., 1000.] mm>
Coordinates:
    u        (x) float64 40B [ms] 0.0 1e+03 2e+03 3e+03 4e+03
Dimensions without coordinates: x