The interpolation library provides the following 2D interpolation types:
Bilinear interpolation. This interpolation method does not require any additional memory.
This function returns the name of the interpolation type used by interp. For example,
printf ("interp uses '%s' interpolation.\n", gsl_interp2d_name (interp));
would print something like,
interp uses 'bilinear' interpolation.
These functions return the minimum number of points required by the interpolation object interp or interpolation type T. For example, bicubic interpolation requires a minimum of 4 points.