IDL版的Marquadt优化算法，可求解非线性最小二乘问题-MPFIT uses the Levenberg-Marquardt technique to solve the

　 least-squares problem.　In its typical use, MPFIT will be used to

　 fit a user-supplied function (the "model") to user-supplied data

　 points (the "data") by adjusting a set of parameters.　MPFIT is

　 based upon MINPACK-1 (LMDIF.F) by More　and collaborators