function z=kbiwe(x,y)

% KBIWE       Bi-weight Kernel Function for univariate data.

if nargin==1,
  z1=15*((1-x.^2).^2)/16;
  z=z1.*(abs(x)<1);
  elseif nargin==2,
    z=kbiwe(x).*kbiwe(y);
end;
