Make Instrument indexable via the na.Indexable mixin (#61)

* Make Instrument indexable via the na.Indexable mixin

AbstractInstrument now inherits named_arrays.Indexable, giving every
instrument a recursive named __getitem__/isel/shape that indexes its fields
(rebuilding dataclasses via dataclasses.replace, so the result is a new
object and cached properties such as `system` are dropped).

A single channel can then be selected generically with
instrument.isel(channel=...) (equivalently instrument[{axis_channel: ...}]),
which extends to any future vectorized selection without a bespoke method
per axis.

Requires named-arrays >= 1.6 (na.Indexable, #180/#181); pin bumped accordingly.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* Bumped `codecov-action` from v5 to v7 to fix the coverage upload step.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

Author: jacobdparker

.github/workflows/tests.yml

@@ -46,7 +46,7 @@ jobs:
           pytest --cov=. --cov-report=xml --cov-report=html
 
       - name: Upload coverage to Codecov
-        uses: codecov/codecov-action@v5
+        uses: codecov/codecov-action@v7
         with:
           token: ${{ secrets.CODECOV_TOKEN }}
           files: coverage.xml

esis/optics/_instruments/_instruments.py

@@ -20,6 +20,7 @@
 
 @dataclasses.dataclass(eq=False, repr=False)
 class AbstractInstrument(
+    na.Indexable,
     optika.mixins.Printable,
     optika.mixins.Rollable,
     optika.mixins.Yawable,

esis/optics/_instruments/_instruments_test.py

@@ -119,3 +119,46 @@ class TestInstrument(
     AbstractTestAbstractInstrument,
 ):
     pass
+
+
+@pytest.mark.parametrize("channel", [0, 1, 2, 3])
+def test_isel(channel: int):
+    """Selecting a channel via the `na.Indexable` interface yields a valid system.
+
+    ``AbstractInstrument`` inherits :class:`named_arrays.Indexable`, so a single
+    channel can be selected with ``instrument.isel(channel=...)`` (equivalently
+    ``instrument[{instrument.axis_channel: ...}]``) without a bespoke method.
+    """
+    instrument = esis.flights.f1.optics.design(num_distribution=0)
+    axis = instrument.axis_channel
+
+    # make a grating orientation and a (dict-stored) ruling coefficient vary by
+    # channel, mimicking a distortion-fit model
+    yaw = na.ScalarArray(np.array([1.0, 2.0, 3.0, 4.0]) * u.deg, axes=axis)
+    coefficient = na.ScalarArray(np.array([10.0, 20.0, 30.0, 40.0]) * u.um, axes=axis)
+    instrument.grating.yaw = yaw
+    instrument.grating.rulings.spacing.coefficients[0] = coefficient
+
+    result = instrument.isel(**{axis: channel})
+
+    # isel and the equivalent dict-indexing agree
+    assert result.grating.yaw.ndarray == instrument[{axis: channel}].grating.yaw.ndarray
+
+    # the selected element is kept and the channel axis is removed
+    assert result.grating.yaw.ndarray == yaw.ndarray[channel]
+    assert axis not in result.grating.yaw.axes
+    assert (
+        result.grating.rulings.spacing.coefficients[0].ndarray
+        == coefficient.ndarray[channel]
+    )
+    assert axis not in result.grating.rulings.spacing.coefficients[0].axes
+    assert axis not in na.as_named_array(result.grating.azimuth).axes
+    assert axis not in na.as_named_array(result.camera.channel).axes
+
+    # the original instrument is left unmodified (na.getitem rebuilds via replace)
+    assert axis in instrument.grating.yaw.axes
+    assert np.all(instrument.grating.yaw.ndarray == yaw.ndarray)
+
+    # the single-channel instrument still resolves into an optical system
+    assert isinstance(result.system, optika.systems.AbstractSequentialSystem)
+    assert result.system.surfaces

pyproject.toml

@@ -19,7 +19,7 @@ dependencies = [
     "matplotlib",
     "astropy~=7.2",
     "joblib",
-    "named-arrays~=1.0",
+    "named-arrays~=1.6",
     "optika~=1.1",
     "msfc-ccd~=1.0",
     "solar-dynamics-observatory~=0.2",