interpax_fft.trig_vander

interpax_fft.trig_vander(x, n, domain=(0, 6.283185307179586))Source

Nyquist trigonometric interpolant basis evaluated at x.

Parameters:

• x (jnp.ndarray) – Points at which to evaluate Vandermonde matrix.

• n (int) – Spectral resolution.

• domain (tuple[float]) – Domain over which samples will be taken. This domain should span an open period of the function to interpolate.

Returns:

vander (jnp.ndarray) – Shape (*x.shape, n). Vandermonde matrix of degree n-1 and sample points x. Last axis ordered as [sin(k𝐱), …, sin(𝐱), 1, cos(𝐱), …, cos(k𝐱)]. When n is even the sin(k𝐱) basis function is excluded.