%
% J=jac(p)
%
function J=jac(p)
global X;
global Y;
global SIGMA;
m=length(p);
n=length(X);
J=zeros(m,n);
for j=1:n
    J(:,j)=([exp(p(2)*X(j)); p(1)*X(j)*exp(p(2)*X(j)); X(j)*exp(p(4)*X(j)); p(3)*X(j)*X(j)*exp(p(4)*X(j))])/SIGMA(j);
end
J=J';

