% -*- texinfo -*-
% @deftypefn {Function File} {@var{pp} = } csape (@var{x}, @var{y}, @var{cond}, @var{valc})
% cubic spline interpolation with various end conditions.
% creates the pp-form of the cubic spline.
%
% the following end conditions as given in @var{cond} are possible.
% @table @asis
% @item 'complete'
% match slopes at first and last point as given in @var{valc}
% @item 'not-a-knot'
% third derivatives are continuous at the second and second last point
% @item 'periodic'
% match first and second derivative of first and last point
% @item 'second'
% match second derivative at first and last point as given in @var{valc}
% @item 'variational'
% set second derivative at first and last point to zero (natural cubic spline)
% @end table
%
% @seealso{ppval, spline}
% @end deftypefn