Add serialization logic for uncertainty objects

CHANGES.rst

@@ -8,6 +8,8 @@
 
 - replace usages of ``copy_arrays`` with ``memmap`` [#230]
 
+- Add support for astropy.nddata.StdDevUncertainty and astropy.nddata.UnknownUncertainty[#239]
+
 0.6.1 (2024-04-05)
 ------------------
 

asdf_astropy/converters/__init__.py

@@ -19,6 +19,9 @@
     "AstropyTableConverter",
     "AsdfTableConverter",
     "NdarrayMixinConverter",
+    "UncertaintyConverter",
+    "StdDevUncertaintyConverter",
+    "UnknownUncertaintyConverter",
     "TimeDeltaConverter",
     "TimeConverter",
     "CompoundConverter",
@@ -73,4 +76,5 @@
     TransformConverterBase,
     UnitsMappingConverter,
 )
+from .uncertainty import StdDevUncertaintyConverter, UncertaintyConverter, UnknownUncertaintyConverter
 from .unit import EquivalencyConverter, MagUnitConverter, QuantityConverter, UnitConverter

asdf_astropy/converters/uncertainty/__init__.py

@@ -0,0 +1,7 @@
+__all__ = [
+    "UncertaintyConverter",
+    "StdDevUncertaintyConverter",
+    "UnknownUncertaintyConverter",
+]
+
+from .uncertainty import StdDevUncertaintyConverter, UncertaintyConverter, UnknownUncertaintyConverter

asdf_astropy/converters/uncertainty/tests/test_uncertainty.py

@@ -0,0 +1,27 @@
+import asdf
+import numpy as np
+import pytest
+from astropy import units as u
+from astropy.nddata import StdDevUncertainty, UnknownUncertainty
+
+
+def create_uncertainty():
+    uncert = np.arange(100).reshape(10, 10)
+    uncertainty_stddev_1 = StdDevUncertainty(uncert, unit="m")
+    uncertainty_stddev_2 = StdDevUncertainty([2], unit="m")
+    uncertainty_unknown_1 = UnknownUncertainty(uncert, unit="m")
+    uncertainty_unknown_2 = UnknownUncertainty([0.4], unit=u.adu)
+    return [uncertainty_stddev_1, uncertainty_stddev_2, uncertainty_unknown_1, uncertainty_unknown_2]
+
+
+@pytest.mark.parametrize("uncertainty", create_uncertainty())
+def test_uncertainty_serialization(uncertainty, tmp_path):
+    file_path = tmp_path / "test_uncertainty.asdf"
+    with asdf.AsdfFile() as af:
+        af["uncertainty"] = uncertainty
+        af.write_to(file_path)
+
+    with asdf.open(file_path) as af:
+        loaded_uncert = af["uncertainty"]
+        assert (loaded_uncert._array == uncertainty._array).all()
+        assert loaded_uncert.unit == uncertainty.unit

asdf_astropy/converters/uncertainty/uncertainty.py

@@ -0,0 +1,40 @@
+from asdf.extension import Converter
+
+
+class UncertaintyConverter(Converter):
+    tags = ("tag:astropy.org:astropy/uncertainty/uncertainty-*",)
+    types = ("astropy.nddata.nduncertainty.Uncertainty",)
+
+    def from_yaml_tree(self, node, tag, ctx):
+        return (node["array"], node.get("unit"))
+
+    def to_yaml_tree(self, nddata_uncertainty, tag, ctx):
+        node = {}
+
+        node["array"] = nddata_uncertainty.array
+        if nddata_uncertainty.unit is not None:
+            node["unit"] = nddata_uncertainty.unit
+
+        return node
+
+
+class StdDevUncertaintyConverter(UncertaintyConverter):
+    tags = ("tag:astropy.org:astropy/uncertainty/stddevuncertainty-*",)
+    types = ("astropy.nddata.nduncertainty.StdDevUncertainty",)
+
+    def from_yaml_tree(self, node, tag, ctx):
+        from astropy.nddata import StdDevUncertainty
+
+        array, unit = super().from_yaml_tree(node, tag, ctx)
+        return StdDevUncertainty(array=array, unit=unit)
+
+
+class UnknownUncertaintyConverter(UncertaintyConverter):
+    tags = ("tag:astropy.org:astropy/uncertainty/unknownuncertainty-*",)
+    types = ("astropy.nddata.nduncertainty.UnknownUncertainty",)
+
+    def from_yaml_tree(self, node, tag, ctx):
+        from astropy.nddata import UnknownUncertainty
+
+        array, unit = super().from_yaml_tree(node, tag, ctx)
+        return UnknownUncertainty(array=array, unit=unit)

asdf_astropy/extensions.py

@@ -27,6 +27,11 @@
 from .converters.transform.rotations import Rotate3DConverter, RotationSequenceConverter
 from .converters.transform.spline import SplineConverter
 from .converters.transform.tabular import TabularConverter
+from .converters.uncertainty.uncertainty import (
+    StdDevUncertaintyConverter,
+    UncertaintyConverter,
+    UnknownUncertaintyConverter,
+)
 from .converters.unit.equivalency import EquivalencyConverter
 from .converters.unit.magunit import MagUnitConverter
 from .converters.unit.quantity import QuantityConverter
@@ -482,6 +487,9 @@
     AstropyTableConverter(),
     AstropyFitsConverter(),
     NdarrayMixinConverter(),
+    UncertaintyConverter(),
+    StdDevUncertaintyConverter(),
+    UnknownUncertaintyConverter(),
 ]
 
 _COORDINATES_MANIFEST_URIS = [

asdf_astropy/resources/manifests/astropy-1.0.0.yaml

@@ -49,3 +49,18 @@ tags:
     This transform operates on the units of the input, first converting to
     the expected input units, then assigning replacement output units without
     further conversion.
+- tag_uri: tag:astropy.org:astropy/uncertainty/uncertainty-1.0.0
+  schema_uri: http://astropy.org/schemas/astropy/uncertainty/uncertainty-1.0.0
+  title: Represent the nddata.uncertainty.NDUncertainty object
+  description: |-
+    Represents an instance of the nddata.uncertainty.NDUncertainty object
+- tag_uri: tag:astropy.org:astropy/uncertainty/unknownuncertainty-1.0.0
+  schema_uri: http://astropy.org/schemas/astropy/uncertainty/unknownuncertainty-1.0.0
+  title: Represent the nddata.uncertainty.UnknownUncertainty object
+  description: |-
+    Represents an instance of the nddata.uncertainty.UnknownUncertainty object
+- tag_uri: tag:astropy.org:astropy/uncertainty/stddevuncertainty-1.0.0
+  schema_uri: http://astropy.org/schemas/astropy/uncertainty/stddevuncertainty-1.0.0
+  title: Represent the nddata.uncertainty.StdDevUncertainty object
+  description: |-
+    Represents an instance of the nddata.uncertainty.StdDevUncertainty object

asdf_astropy/resources/schemas/uncertainty/stddevuncertainty-1.0.0.yaml

@@ -0,0 +1,22 @@
+%YAML 1.1
+---
+$schema: "http://stsci.edu/schemas/yaml-schema/draft-01"
+id: "http://astropy.org/schemas/astropy/uncertainty/stddevuncertainty-1.0.0"
+
+title:
+  Represents the astropy.nddata.StdDevUncertainty class
+
+description:
+  This object represents the `StdDevUncertainty` class, which is a subclass
+  of the `NDUncertainty` class from `astropy.nddata`
+
+allOf:
+  - tag: "tag:astropy.org:astropy/uncertainty/stddevuncertainty-1.0.0"
+  - type: object
+    properties:
+      array:
+        type: object
+      unit:
+        anyOf:
+          - tag: "tag:stsci.edu:asdf/unit/unit-*"
+          - tag: "tag:astropy.org:astropy/units/unit-1.*"

asdf_astropy/resources/schemas/uncertainty/uncertainty-1.0.0.yaml

@@ -0,0 +1,21 @@
+%YAML 1.1
+---
+$schema: "http://stsci.edu/schemas/yaml-schema/draft-01"
+id: "http://astropy.org/schemas/astropy/uncertainty/uncertainty-1.0.0"
+
+title:
+  Represents the astropy.nddata.NDUncertainty object
+
+description:
+  Represents the astropy.nddata.NDUncertainty object
+
+allOf:
+  - tag: "tag:astropy.org:astropy/uncertainty/uncertainty-1.0.0"
+  - type: object
+    properties:
+      array:
+        type: object
+      unit:
+        anyOf:
+          - tag: "tag:stsci.edu:asdf/unit/unit-*"
+          - tag: "tag:astropy.org:astropy/units/unit-1.*"

asdf_astropy/resources/schemas/uncertainty/unknownuncertainty-1.0.0.yaml

@@ -0,0 +1,22 @@
+%YAML 1.1
+---
+$schema: "http://stsci.edu/schemas/yaml-schema/draft-01"
+id: "http://astropy.org/schemas/astropy/uncertainty/unknownuncertainty-1.0.0"
+
+title:
+  Represents the astropy.nddata.UnknownUncertainty class
+
+description:
+  This object represents the `UnknownUncertainty` class, which is a subclass
+  of the `NDUncertainty` class from `astropy.nddata`
+
+allOf:
+  - tag: "tag:astropy.org:astropy/uncertainty/unknownuncertainty-1.0.0"
+  - type: object
+    properties:
+      array:
+        type: object
+      unit:
+        anyOf:
+          - tag: "tag:stsci.edu:asdf/unit/unit-*"
+          - tag: "tag:astropy.org:astropy/units/unit-1.*"