Function

NumCosmoMathSpectralgegenbauer_alpha1_eval

Declaration [src]

gdouble
ncm_spectral_gegenbauer_alpha1_eval (
  GArray* c,
  gdouble t
)

Description [src]

Evaluates a Gegenbauer $C^{(1)}_n$ expansion at t using Clenshaw recurrence. For $\alpha=1$, $C^{(1)}_n(t) = U_n(t)$ (Chebyshev polynomials of the second kind). The variable t should be in the interval [-1, 1]. To evaluate at a point x in [a, b], use ncm_spectral_gegenbauer_alpha1_eval_x() or first convert x to t using ncm_spectral_x_to_t().

Parameters

c

Type: An array of double

Gegenbauer $C^{(1)}_n$ coefficients array.

The data is owned by the caller of the function.
t

Type: gdouble

Point to evaluate in [-1, 1].

Return value

Type: gdouble

The value of $\sum_{n=0}^{N-1} c_n C^{(1)}_n(t)$.