function  [f, df] = regpoly1(S)%REGPOLY1  First order polynomial regression function%% Call:    f = regpoly1(S)%          [f, df] = regpoly1(S)%% S : m*n matrix with design sites% f = [1  s]% df : Jacobian at the first point (first row in S) % hbn@imm.dtu.dk  % Last update April 12, 2002[m n] = size(S);f = [ones(m,1)  S];if  nargout > 1  df = [zeros(n,1) eye(n)];end