NcmSFSBessel

NcmSFSBessel — Double precision spherical bessel implementation.

Description

FIXME

Functions

ncm_sf_sbessel ()

gdouble
ncm_sf_sbessel (gulong l,
                gdouble x);

Computes Spherical Bessel function $j_\ell(x)$.

Parameters

l

Spherical Bessel order $\ell$

 

x

Spherical Bessel argument $x$

 

Returns

the value of $j_\ell(x)$.


ncm_sf_sbessel_taylor ()

void
ncm_sf_sbessel_taylor (gulong l,
                       gdouble x,
                       gdouble *djl);

Computes Spherical Bessel function power series coefficients up to order three, i.e., $$\left(j_\ell(x),\; j'_\ell(x), \frac{j''_\ell(x)}{2!}, \frac{j'''_\ell(x)}{3!}\right).$$

Parameters

l

Spherical Bessel order $\ell$

 

x

Spherical Bessel argument $x$

 

djl

Output power series coefficients.

[out][array fixed-size=4]

ncm_sf_sbessel_spline ()

NcmSpline *
ncm_sf_sbessel_spline (gulong l,
                       gdouble xi,
                       gdouble xf,
                       gdouble reltol);

Computes a spline approximation of the Spherical Bessel $j_\ell$ in the interval $[x_i, x_f]$.

Parameters

l

Spherical Bessel order $\ell$.

 

xi

Spherical Bessel interval lower-bound $x_i$.

 

xf

Spherical Bessel interval lower-bound $x_f$.

 

reltol

Interpolation error tolerance.

 

Returns

A NcmSpline with the Spherical Bessel approximation.

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