Function

NumCosmoMathSpectralchebyshev_eval_x

Declaration [src]

gdouble
ncm_spectral_chebyshev_eval_x (
  GArray* a,
  gdouble a_v,
  gdouble b,
  gdouble x
)

Description [src]

Evaluates a Chebyshev expansion at a point x in [a_v, b]. This function converts x to t using $t = (2x - (a_v+b))/(b-a_v)$ and then calls ncm_spectral_chebyshev_eval().

Parameters

a

Type: An array of double

Chebyshev coefficients array.

The data is owned by the caller of the function.

a_v

Type: gdouble

Left endpoint of the interval.

b

Type: gdouble

Right endpoint of the interval.

x

Type: gdouble

Point to evaluate in [a_v, b].

Return value

Type: gdouble

The value of $\sum_{k=0}^{N-1} a_k T_k(t)$ where $t = (2x - (a_v+b))/(b-a_v)$.