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fmm.fourier_matrices_patterned_isotropic_media

fmm.fourier_matrices_patterned_isotropic_media​

Return Fourier convolution matrices for patterned nonmagnetic isotropic media.

All matrices are forms of the Fourier convolution matrices defined in equation 8 of [2012 Liu]. For vector formulations, the transverse permittivity matrix is of the form E2 given in equation 51 of [2012 Liu].

Args:​

  • primitive_lattice_vectors: The primitive vectors for the real-space lattice.
  • permittivity: The permittivity array, with shape (..., nx, ny).
  • expansion: The field expansion to be used.
  • formulation: Specifies the formulation to be used, or a callable which computes the tangent vector field for a custom vector FMM formulation.

Returns:​

  • inverse_z_permittivity_matrix: The Fourier convolution matrix for the inverse of the z-component of the permittivity. z_permittivity_matrix: The Fourier convolution matrix for the z-component of the permittivity. transverse_permittivity_matrix: The transverse permittivity matrix. tangent_vector_field: The tangent vector field (tx, ty) used to compute the transverse permittivity matrix, if a vector FMM formulation is used. If the FFT formulation is used, the vector field is None.