function[F,J] = nlsf1(x)
%NLSF1  Nonlinear vector-valued function and Jacobian

%   Copyright 1990-2004 The MathWorks, Inc.
%   $Revision: 1.5.4.2 $  $Date: 2004/07/28 04:28:59 $
%   Thomas F. Coleman 7-1-96

% Evaluate the vector function
n = length(x);
F = zeros(n,1);
i = 2:(n-1);
F(i) = (3-2*x(i)).*x(i)-x(i-1)-2*x(i+1) + 1;
F(n) = (3-2*x(n)).*x(n)-x(n-1) + 1;
F(1) = (3-2*x(1)).*x(1)-2*x(2) + 1;
% Evaluate the Jacobian if nargout > 1
if nargout > 1
   d = -4*x + 3*ones(n,1); D = sparse(1:n,1:n,d,n,n);
   c = -2*ones(n-1,1); C = sparse(1:n-1,2:n,c,n,n);
   e = -ones(n-1,1); E = sparse(2:n,1:n-1,e,n,n);
   J = C + D + E;
end