define visibility class API (#55)

Introduce new API for handling visibilities: `~xrayvision.visibility.VisibilitiesABC` and `~xrayvision.visibility.VisMetaABC`, along with implemented versions of the classes `~xrayvision.visibility.Visibilities` and `~xrayvision.visibility.VisMeta`.


Co-authored-by: DanRyanIrish <[email protected]>
Co-authored-by: Shane Maloney <[email protected]>

changelog/55.feature.rst

@@ -0,0 +1 @@
+Introduce new API for handling visibilities: `~xrayvision.visibility.VisibilitiesABC` and `~xrayvision.visibility.VisMetaABC`, along with implemented versions of the classes `~xrayvision.visibility.Visibilities` and `~xrayvision.visibility.VisMeta`.

setup.cfg

@@ -35,6 +35,7 @@ install_requires =
     astropy>=3.4.1
     numpy>=1.17.0
     scipy>=1.3.0
+    xarray
 [options.extras_require]
 map =
     sunpy[map]>=3.1.0

xrayvision/tests/test_visibility.py

@@ -1,9 +1,72 @@
 from pathlib import Path
 
+import astropy.units as apu
 import pytest
+from astropy.tests.helper import assert_quantity_allclose
+
+import xrayvision.visibility as vm
 
 
 @pytest.fixture
 def test_data_dir():
     path = Path(__file__).parent.parent / "data"
     return path
+
+
+@pytest.fixture
+def visibilities():
+    visibilities = [1 + 2 * 1j, 3 + 3 * 1j] * apu.ct
+    u = [0.023, -0.08] * 1 / apu.arcsec
+    v = [-0.0013, 0.013] * 1 / apu.arcsec
+    phase_center = [0, 0] * apu.arcsec
+    unc = [0.01, 0.15] * apu.ct
+    meta = {"vis_labels": ["3a", "10b"]}
+    return vm.Visibilities(visibilities, u, v, phase_center, uncertainty=unc, meta=meta)
+
+
+def test_vis_u(visibilities):
+    vis_base = visibilities
+    output_u = vis_base.u
+    expected_u = [0.023, -0.08] * 1 / apu.arcsec
+
+    assert_quantity_allclose(output_u, expected_u)
+
+
+def test_vis_v(visibilities):
+    vis_base = visibilities
+    output_v = vis_base.v
+    expected_v = [-0.0013, 0.013] * 1 / apu.arcsec
+
+    assert_quantity_allclose(output_v, expected_v)
+
+
+def test_vis_amplitude(visibilities):
+    vis_base = visibilities
+    output_amplitude = vis_base.amplitude
+    expected_amplitude = [2.236068, 4.2426407] * apu.ct
+
+    assert_quantity_allclose(output_amplitude, expected_amplitude)
+
+
+def test_vis_phase(visibilities):
+    vis_base = visibilities
+    output_phase = vis_base.phase
+    expected_phase = [63.434949, 45] * apu.deg
+
+    assert_quantity_allclose(output_phase, expected_phase)
+
+
+def test_vis_amplitude_uncertainty(visibilities):
+    vis_base = visibilities
+    output_amplitude_uncertainty = vis_base.amplitude_uncertainty
+    expected_amplitude_uncertainty = [0.004472136, 0.10606602] * apu.ct
+
+    assert_quantity_allclose(output_amplitude_uncertainty, expected_amplitude_uncertainty)
+
+
+def test_vis_phase_uncertainty(visibilities):
+    vis_base = visibilities
+    output_phase_uncertainty = vis_base.phase_uncertainty
+    expected_phase_uncertainty = [0.22918312, 1.4323945] * apu.deg
+
+    assert_quantity_allclose(output_phase_uncertainty, expected_phase_uncertainty)