Fix to fully anisotropic eps_model when an array of freqs is provided

Author: momchil-flex

tests/test_components/test_medium.py

@@ -450,6 +450,9 @@ def test_fully_anisotropic_media():
         rotation=rot,
     )
 
+    # check eps_model can be called with an array of frequencies
+    eps = m.eps_model(np.linspace(1e12, 2e12, 10))
+
     assert np.allclose(m.permittivity, perm)
     assert np.allclose(m.conductivity, cond)
 

tidy3d/components/medium.py

@@ -3606,6 +3606,9 @@ def eps_model(self, frequency: float) -> complex:
         """Complex-valued permittivity as a function of frequency."""
         perm_diag, cond_diag, _ = self.eps_sigma_diag
 
+        if not np.isscalar(frequency):
+            perm_diag = perm_diag[:, None]
+            cond_diag = cond_diag[:, None]
         eps_diag = AbstractMedium.eps_sigma_to_eps_complex(perm_diag, cond_diag, frequency)
         return np.mean(eps_diag)