Electron-based instrument interface and OptikaInstrument

ctis/_regrid.py

@@ -151,6 +151,11 @@ def regrid(
 
     axis = (axis_wavelength, *axis_position)
 
+    # normalize to plain spectral-positional vectors so grids defined on a
+    # Doppler vector (as produced by the `IdealInstrument`) are accepted.
+    coordinates_input = coordinates_input.spectral_positional
+    coordinates_output = coordinates_output.spectral_positional
+
     # weight each input voxel by its volume so the conservative regridding
     # preserves the integral of the field rather than the per-voxel sum.
     values = values_input * coordinates_input.volume_cell(axis)

ctis/_regrid_test.py

@@ -17,6 +17,22 @@ def _grid(num_wavelength: int, num_position: int) -> na.SpectralPositionalVector
     )
 
 
+def _grid_doppler(
+    num_wavelength: int,
+    num_position: int,
+) -> na.DopplerPositionalVectorArray:
+    return na.DopplerPositionalVectorArray(
+        wavelength=na.linspace(500, 600, axis="wavelength", num=num_wavelength) * u.nm,
+        wavelength_rest=550 * u.nm,
+        position=na.Cartesian2dVectorLinearSpace(
+            start=-10 * u.arcsec,
+            stop=+10 * u.arcsec,
+            axis=na.Cartesian2dVectorArray("x", "y"),
+            num=num_position,
+        ),
+    )
+
+
 @pytest.mark.parametrize(
     argnames="coordinates_input,coordinates_output",
     argvalues=[
@@ -69,3 +85,41 @@ def test_regrid(
     integral_output = (result * coordinates_output.volume_cell(axis)).sum()
     ratio = float((integral_output / integral_input).ndarray)
     assert np.isclose(ratio, 1, rtol=0.05)
+
+
+def test_regrid_doppler():
+    # grids defined on a Doppler vector (as produced by the `IdealInstrument`)
+    # are accepted, normalized to spectral-positional for the volume weighting.
+    axis_wavelength = "wavelength"
+    axis_position = ("x", "y")
+    coordinates_input = _grid_doppler(9, 13)
+    coordinates_output = _grid_doppler(5, 7)
+
+    num_input = coordinates_input.shape
+    values_input = na.random.uniform(
+        low=0,
+        high=1,
+        shape_random={
+            axis_wavelength: num_input[axis_wavelength] - 1,
+            axis_position[0]: num_input[axis_position[0]] - 1,
+            axis_position[1]: num_input[axis_position[1]] - 1,
+        },
+    )
+
+    result = ctis.regrid(
+        coordinates_input=coordinates_input,
+        coordinates_output=coordinates_output,
+        values_input=values_input,
+        axis_wavelength=axis_wavelength,
+        axis_position=axis_position,
+    )
+
+    assert isinstance(result, na.AbstractScalarArray)
+    assert np.all(np.isfinite(result))
+
+    num_output = coordinates_output.shape
+    assert na.shape(result) == {
+        axis_wavelength: num_output[axis_wavelength] - 1,
+        axis_position[0]: num_output[axis_position[0]] - 1,
+        axis_position[1]: num_output[axis_position[1]] - 1,
+    }

ctis/instruments/__init__.py

@@ -6,10 +6,12 @@
     AbstractInstrument,
     AbstractLinearInstrument,
     IdealInstrument,
+    OptikaInstrument,
 )
 
 __all__ = [
     "AbstractInstrument",
     "AbstractLinearInstrument",
     "IdealInstrument",
+    "OptikaInstrument",
 ]