title: Python equivalence of Matlab lsqcurvefit() function
body: <p>What is the equivalent or closest python, say SciPy, function to the Matlab function lsqcurvefit() which minimizes the square error between the data and a parameterized function (curve)?</p>
  
  <p>I know scipy.optimize.curve_fit and scipy.optimize.leastsq are close. However, they do not use trust region relfective least square method. Of course, I can code the condition for switching between algorithms myself. But if there are existing python code, I do not have to reinvent the wheel.</p>