% -*- texinfo -*-
% @deftypefn {Function File} {@var{pp}} = catmullrom( @var{x},@
% @var{f}, @var{v})
%
% Returns the piecewise polynomial form of the Catmull-Rom cubic
% spline interpolating @var{f} at the points @var{x}.
% If the input @var{v} is supplied it will be interpreted as the
% values of the tangents at the extremals, if it is
% missing, the values will be computed from the data via one-sided
% finite difference formulas. See the wikipedia page for 'Cubic
% Hermite spline' for a description of the algorithm.
%
% @seealso{ppval}
% @end deftypefn