% -*- texinfo -*-
% @deftypefn{Function File}{[@var{yi}, @var{p}] =} csaps(@var{x}, @var{y}, @var{p}, @var{xi}, @var{w}=[])
% @deftypefnx{Function File}{[@var{pp}, @var{p}] =} csaps(@var{x}, @var{y}, @var{p}=-1, [], @var{w}=[])
%
% Cubic spline approximation (smoothing)@*
% approximate [x,y] weighted w at xi
%
% @table @asis
% @item @var{p}<0
% automatic smoothing
% @item @var{p}=0
% maximum smoothing: straight line
% @item @var{p}=1
% no smoothing: interpolation
% @end table
%
% @seealso{csapi, ppval, gcvspl}
% @end deftypefn