[Help-gsl] Adding higher level interface for 2D extrapolation function

[Brijesh Upadhaya]

Hi!

I am currently using 2D interpolation with Bicubic spline and I have found
out that there was no higher level interface for extrapolation function.
Thus, I have added the following function in my work code:

static double
> gsl_spline2d_eval_extrap (const gsl_spline2d * interp, const double x,
>                                        const double y, gsl_interp_accel *
> xa,
>                                         gsl_interp_accel * ya)
> {
>   return gsl_interp2d_eval_extrap (&(interp->interp_object), interp->xarr,
>                                    interp->yarr, interp->zarr, x, y, xa,
> ya);
> }
>

I hope this could be added in the future release of GSL.

Kind regards,
Brijesh