interpax_fft.rfft_to_trig

interpax_fft.rfft_to_trig(a, n, axis=-1)Source

Spectral coefficients of the Nyquist trigonometric interpolant.

Parameters:

  • a (jnp.ndarray) – Fourier coefficients a=rfft(f,norm="forward",axis=axis).

  • n (int) – Spectral resolution of a.

  • axis (int) – Axis along which coefficients are stored.

Returns:

h (jnp.ndarray) – Nyquist trigonometric interpolant coefficients.

Coefficients are ordered along axis of size n to match Vandermonde matrix with order [sin(k𝐱), …, sin(𝐱), 1, cos(𝐱), …, cos(k𝐱)]. When n is even the sin(k𝐱) coefficient is zero and is excluded.