Function
NumCosmoMathSpectralchebyshev_deriv_x
Declaration [src]
gdouble
ncm_spectral_chebyshev_deriv_x (
GArray* a,
gdouble a_v,
gdouble b,
gdouble x
)
Description [src]
Evaluates the first derivative of a Chebyshev expansion at a point x in [a_v, b]. This function converts x to t using $t = (2x - (a_v+b))/(b-a_v)$, evaluates the derivative with respect to t using ncm_spectral_chebyshev_deriv(), and then applies the chain rule: $df/dx = (df/dt) \cdot (dt/dx) = (df/dt) \cdot 2/(b-a_v)$.