Various improvements to EME solver.

tests/test_plugins/test_adjoint.py

@@ -1990,8 +1990,8 @@ def test_no_poynting(use_emulated_run):
 
     sim_data._get_scalar_field(mnt_name_static, "S", "abs")
 
-    with pytest.raises(NotImplementedError):
-        sim_data._get_scalar_field(mnt_name_differentiable, "S", "abs")
+    # with pytest.raises(NotImplementedError):
+    #    sim_data._get_scalar_field(mnt_name_differentiable, "S", "abs")
 
 
 def test_to_gds(tmp_path):

tests/test_plugins/test_mode_solver.py

@@ -812,7 +812,7 @@ def test_mode_solver_nan_pol_fraction():
     md = ms.solve()
     check_ms_reduction(ms)
 
-    assert list(np.where(np.isnan(md.pol_fraction.te))[1]) == [8, 9]
+    assert list(np.where(np.isnan(md.pol_fraction.te))[1]) == [9]
 
 
 def test_mode_solver_method_defaults():
@@ -906,5 +906,39 @@ def test_mode_solver_web_run_batch(mock_remote_api):
     # Run mode solver one at a time
     results = msweb.run_batch(mode_solver_list, verbose=False, folder_name="Mode Solver")
     [print(type(x)) for x in results]
-    assert all([isinstance(x, ModeSolverData) for x in results])
+    assert all(isinstance(x, ModeSolverData) for x in results)
     assert (results[i].n_eff.shape == (num_freqs, i + 1) for i in range(num_of_sims))
+
+
+def test_mode_solver_relative():
+    """Relative mode solver"""
+
+    simulation = td.Simulation(
+        size=SIM_SIZE,
+        grid_spec=td.GridSpec(wavelength=1.0),
+        structures=[WAVEGUIDE],
+        run_time=1e-12,
+        symmetry=(0, 0, 1),
+        boundary_spec=td.BoundarySpec.all_sides(boundary=td.Periodic()),
+        sources=[SRC],
+    )
+    mode_spec = td.ModeSpec(
+        num_modes=3,
+        target_neff=2.0,
+        filter_pol="tm",
+        precision="double",
+        track_freq="lowest",
+    )
+    freqs = [td.C_0 / 0.9, td.C_0 / 1.0, td.C_0 / 1.1]
+    ms = ModeSolver(
+        simulation=simulation,
+        plane=PLANE,
+        mode_spec=mode_spec,
+        freqs=freqs,
+        direction="-",
+        colocate=False,
+    )
+    basis = ms.data_raw
+    new_freqs = np.array(freqs) * 1.01
+    ms = ms.updated_copy(freqs=new_freqs)
+    _ = ms._data_on_yee_grid_relative(basis=basis)

tidy3d/__init__.py

@@ -156,7 +156,7 @@
 from .components.eme.data.monitor_data import EMEModeSolverData, EMEFieldData, EMECoefficientData
 from .components.eme.grid import EMEUniformGrid, EMECompositeGrid, EMEExplicitGrid
 from .components.eme.grid import EMEGrid, EMEModeSpec
-from .components.eme.sweep import EMELengthSweep, EMEModeSweep
+from .components.eme.sweep import EMELengthSweep, EMEModeSweep, EMEFreqSweep
 
 
 def set_logging_level(level: str) -> None:
@@ -387,4 +387,5 @@ def set_logging_level(level: str) -> None:
     "EMESweepSpec",
     "EMELengthSweep",
     "EMEModeSweep",
+    "EMEFreqSweep",
 ]

tidy3d/components/data/data_array.py

@@ -779,7 +779,7 @@ class EMEScalarModeFieldDataArray(AbstractSpatialDataArray):
     """
 
     __slots__ = ()
-    _dims = ("x", "y", "z", "f", "mode_index", "eme_cell_index")
+    _dims = ("x", "y", "z", "f", "sweep_index", "eme_cell_index", "mode_index")
 
 
 class EMEFreqModeDataArray(DataArray):
@@ -795,7 +795,7 @@ class EMEFreqModeDataArray(DataArray):
     """
 
     __slots__ = ()
-    _dims = ("f", "mode_index", "eme_cell_index")
+    _dims = ("f", "sweep_index", "eme_cell_index", "mode_index")
 
 
 class EMEScalarFieldDataArray(AbstractSpatialDataArray):
@@ -815,7 +815,7 @@ class EMEScalarFieldDataArray(AbstractSpatialDataArray):
     """
 
     __slots__ = ()
-    _dims = ("x", "y", "z", "f", "mode_index", "eme_port_index")
+    _dims = ("x", "y", "z", "f", "sweep_index", "eme_port_index", "mode_index")
 
 
 class EMECoefficientDataArray(DataArray):
@@ -836,11 +836,18 @@ class EMECoefficientDataArray(DataArray):
     ...     eme_cell_index=eme_cell_index,
     ...     eme_port_index=eme_port_index
     ... )
-    >>> fd = EMESMatrixDataArray((1 + 1j) * np.random.random((1, 2, 2, 5, 2)), coords=coords)
+    >>> fd = EMECoefficientDataArray((1 + 1j) * np.random.random((1, 2, 2, 5, 2)), coords=coords)
     """
 
     __slots__ = ()
-    _dims = ("f", "mode_index_out", "mode_index_in", "eme_cell_index", "eme_port_index")
+    _dims = (
+        "f",
+        "sweep_index",
+        "eme_port_index",
+        "eme_cell_index",
+        "mode_index_out",
+        "mode_index_in",
+    )
     _data_attrs = {"long_name": "mode expansion coefficient"}
 
 
@@ -864,7 +871,7 @@ class EMESMatrixDataArray(DataArray):
     """
 
     __slots__ = ()
-    _dims = ("f", "mode_index_out", "mode_index_in", "sweep_index")
+    _dims = ("f", "sweep_index", "mode_index_out", "mode_index_in")
     _data_attrs = {"long_name": "scattering matrix element"}
 
 
@@ -882,7 +889,7 @@ class EMEModeIndexDataArray(DataArray):
     """
 
     __slots__ = ()
-    _dims = ("f", "mode_index", "eme_cell_index")
+    _dims = ("f", "sweep_index", "eme_cell_index", "mode_index")
     _data_attrs = {"long_name": "Propagation index"}