title: Tolerance for termination
body: <p>For example this page (<a href="http://docs.scipy.org/doc/scipy/reference/optimize.minimize-lbfgsb.html" rel="nofollow noreferrer">http://docs.scipy.org/doc/scipy/reference/optimize.minimize-lbfgsb.html</a>) describes the solver options one can pass to the L-BFGS-B' method of scipy's optimization package. I am trying to set the solver exit tolerance for some methods (L-BFGS-B, Nelder-Mead, TNC).</p>
  
  <p>I put <code>'tol':0.001</code> but I don't understand why the solver stop this converge with an <code>error = 0.49</code>.</p>
  
  <p>I assume that the tolerance is the difference between my function's return and the value of tolerance. So for me, the solver must be converge if error is inferior than 0.001, but not for <code>error = 0.49</code>!</p>
  
  <p>How can I set my convergence tolerance ? With specific options like <code>gtol</code> or <code>ftol</code>  ?</p>
  
  <p>Thank you very much!</p>