added tests for spherical mesh

tests/unit_tests/test_spherical_mesh.py

@@ -1,16 +1,42 @@
+from itertools import product, permutations
+
 import openmc
 import numpy as np
 
-def test_origin_read_write_to_xml():
-    """Tests that the origin attribute can be written and read back to XML
-    """
+import pytest
+
+geom_size = 5
+
+@pytest.fixture()
+def model():
+    openmc.reset_auto_ids()
+
+    water = openmc.Material(name='water')
+    water.add_element('H', 2.0)
+    water.add_element('O', 1.0)
+    water.set_density('g/cc', 1.0)
+
+    rpp = openmc.model.RectangularParallelepiped(*([-geom_size, geom_size] * 3),
+                                                 boundary_type='vacuum')
+
+    cell = openmc.Cell(region=-rpp, fill=water)
+
+    geom = openmc.Geometry([cell])
+
+    source = openmc.Source()
+    source.space = openmc.stats.Point()
+    source.energy = openmc.stats.Discrete([10000], [1.0])
+
+    settings = openmc.Settings()
+    settings.particles = 1000
+    settings.batches = 10
+    settings.run_mode = 'fixed source'
+
     # build
     mesh = openmc.SphericalMesh()
-    mesh.phi_grid = [1, 2, 3]
-    mesh.theta_grid = [1, 2, 3]
-    mesh.r_grid = [1, 2, 3]
-
-    mesh.origin = [0.1, 0.2, 0.3]
+    mesh.phi_grid = np.linspace(0, 2*np.pi, 21)
+    mesh.theta_grid = np.linspace(0, 2*np.pi, 11)
+    mesh.r_grid = np.linspace(0, geom_size, geom_size)
 
     tally = openmc.Tally()
 
@@ -21,10 +47,52 @@ def test_origin_read_write_to_xml():
 
     tallies = openmc.Tallies([tally])
 
-    tallies.export_to_xml()
+    return openmc.Model(geometry=geom, settings=settings, tallies=tallies)
+
+def test_origin_read_write_to_xml(run_in_tmpdir, model):
+    """Tests that the origin attribute can be written and read back to XML
+    """
+    mesh = model.tallies[0].filters[0].mesh
+    mesh.origin = [0.1, 0.2, 0.3]
+    model.tallies.export_to_xml()
 
     # read back
     new_tallies = openmc.Tallies.from_xml()
     new_tally = new_tallies[0]
     new_mesh = new_tally.filters[0].mesh
-    assert np.allclose(new_mesh.origin, mesh.origin)
+    np.testing.assert_equal(new_mesh.origin, mesh.origin)
+
+estimators = ('tracklength', 'collision')
+origins = permutations([-geom_size, 0, 0])
+
+test_cases = product(estimators, origins)
+
+def label(p):
+    if isinstance(p, tuple):
+        return f'origin:{p}'
+    if isinstance(p, str):
+        return f'estimator:{p}'
+
+@pytest.mark.parametrize('estimator,origin', test_cases, ids=label)
+def test_offset_mesh(model, estimator, origin):
+    """Tests that the mesh has been moved based on tally results
+    """
+    mesh = model.tallies[0].filters[0].mesh
+    model.tallies[0].estimator = estimator
+    # move the center of the spherical mesh upwards
+    mesh.origin = origin
+
+    sp_filename = model.run()
+
+    with openmc.StatePoint(sp_filename) as sp:
+        tally = sp.tallies[1]
+
+        # we've translated half of the spherical mesh above the model,
+        # so ensure that half of the bins are populated
+        assert np.count_nonzero(tally.mean) == tally.mean.size / 2
+
+        # check that the lower half of the mesh contains a tally result
+        # and that the upper half is zero
+        mean = tally.mean.reshape(mesh.dimension[::-1]).T
+        # assert np.count_nonzero(mean[:, :, :5]) == mean.size / 2
+        # assert np.count_nonzero(mean[:, :, 5:]) == 0