interpax_fft.rfft2_vander

interpax_fft.rfft2_vander(x_fft, x_rfft, modes_fft, modes_rfft, x_fft0=0, x_rfft0=0, inverse_idx_fft=None, inverse_idx_rfft=None)Source

Return Vandermonde matrix for complex Fourier modes.

Parameters:

  • x_fft (jnp.ndarray) – Real query points of coordinate in domain_fft where interpolation is desired.

  • x_rfft (jnp.ndarray) – Real query points of coordinate in domain_rfft where interpolation is desired.

  • modes_fft (jnp.ndarray) – FFT Fourier modes.

  • modes_rfft (jnp.ndarray) – Real FFT Fourier modes.

  • x_fft0 (float) – Left boundary of domain of coordinate specified by x_fft over which samples were taken.

  • x_rfft0 (float) – Left boundary of domain of coordinate specified by x_rfft over which samples were taken.

  • inverse_idx_fft (jnp.ndarray) – Optional. Inverse idx along axis 0 to ensure query points broadcast.

  • inverse_idx_rfft (jnp.ndarray) – Optional. Inverse idx along axis 0 to ensure query points broadcast.

Returns:

vander (jnp.ndarray) – Shape (…, modes_fft.size, modes_rfft.size). Vandermonde matrix to evaluate complex Fourier series.