The interpolation function for a given dataset is stored in a
gsl_interp object. These are created by the following functions.
This function returns a pointer to a newly allocated interpolation object of type T for size data-points.
This function initializes the interpolation object interp for the
data (xa,ya) where xa and ya are arrays of size
size. The interpolation object (
gsl_interp) does not save
the data arrays xa and ya and only stores the static state
computed from the data. The xa data array is always assumed to be
strictly ordered, with increasing x values;
the behavior for other arrangements is not defined.
This function frees the interpolation object interp.